purge tech review

7/21/2019 Purge Tech Review

1/16T1The Leaders in Purging Techn ologyTM www.bebcoeps.com

Pepperl+Fuchs, Inc. Purge/Pressurization Systems Technology Revie

H a n d b o o k C o n te n ts

The nee d to place genera l purpose eq uipment in haz ardo us

(clas sified ) loca tions is not new, yet in the las t three d ec ad esthe nee d ha s intensifie d d rama tica lly. This is primarily due to

the follow ing fac ts:

Proces s c ontrol, meas uring a nd recording eq uipment that

was once primarily pneumatic is now primarily general

purpose electronic eq uipment.

Motors and sw itchgea r now use electronic a cc ess ories to

satisfy the needs for position, speed or process control

and energy efficiency, which often renders the equipment

unsuitab le for use in ha za rdous loca tions.

Newly developed eq uipment, such as robotic manipulators,

CNCs , batc h weigh/co unt a nd filling sys tems, a nalyzers,

programmab le c ontrollers a nd C RT work s ta t ions a re

rapidly becoming more prevalent in the industrial workenvironment.

While the de ma nd for these new d evice s co ntinues to

grow, most of them cannot be economically installed in ahazardous location by using explosion proof enclosures

or intrinsic safety barriers, alone. Most modern electronic

eq uipment is expens ive and de lica te. For this reas on, it

requires environmental protection that cannot be provided

by explosion proof e nclosures o r intrinsic s afety ba rriers.

Therefore, the nee d for a n a lterna tive to explos ion proof

enclosures a nd intrinsic sa fety ba rriers has bec ome extremely

critical.

The alternative is purge and pressurization.

As you learn mo re a bo ut it will

become apparent that this technology is exactly what you

require. It will then become obvious that this technology

offers the safest and most economical means of installingelectrica l eq uipment in a ha za rdous loca tion. In ad dition, this

technolog y w ill undoub tedly impress you a s the only defi nitive

way to enhance your eq uipment's performanc e and a cc ess ,

while increas ing the life expec tanc y of d elica te instruments.

Fina lly, you'll lea rn the mo st impo rta nt point of a ll:

The answer to your need is Pepperl+Fuchs Bebco EPS.

A Pepperl+Fuchs Bebco Rapid ExchangeTMPurging Systemand several accessories make this enclosure acceptable forClass I, Group C & D, Division 2 hazardous locations.

This MSA Monitor is protected with a Pepperl+FuchsBebco Model 1001A Type "Z" Purg ing System making itsuitable for Class I, Group A-D, Division 2 hazardous locations.

D e fin in g th e N e e d

INTRODUCTION

Defining the Need Page T1

Examining the Solutions Page T2

STUDY GUIDE

Defining Hazardous Areas Page T4

Common Questions Page T5

NFPA & ISA Design Standards Page T6

Pressurization System Designs Page T7

DESIGN GUIDE

Typical Enclosure Connections Page T8

Indicators, Alarms & Cutoffs Page T9

Enclosure Marking & Wiring Page T10

Basic Operating Procedures Page T11

APPLICATION GUIDE

Enclosure Design Considerations Page T12

Device Use Considerations Pages T13 - T14

Typical Applications Pages T15 - T16


2/16T2

INTROD

UCTION

The Leaders in Purging Techn ologyTM www.bebcoeps.com

Pepperl+Fuchs, Inc. Purge/Pressurization Systems Technology Review

Exa m ining the So lut io ns

Explos ion P roof Enc losure s

Intent

These enc los ures are des igne d to co ntain an explos ion if a n

electrica l device ignites fla mma ble substa nce s within the enc los ure,

thus preventing ig nition of the surround ing a tmo sp here. Thes eenc los ures a re commo nly used for circuit brea kers, mec hanica l

sw itchg ea rs a nd high-powe red eq uipment. The failure to prope rly

tighten all bolts and screw covers on these enclosures is the

greatest problem fac ing end users.

Advantages

Explosion Containment No Electronics

Requires Low Maintenance No Moving Pa rts

High-Powered Equipment

Disadvantages

Ca nnot Indicate Failure of Co ntainment Ca pab ility

Da ng er to Eq uipme nt After Explosions

P os sibility of Insta lla tion/Maintena nce Errors

Co st of Protec tion per ft3 Increases With Enclosure Size

Windows are Limited

Promotes Condensation Limited Sizes

Cumbersome, Limited Access Bulky Designs

Ca uses Ha rmful Heat B uild up Excessive Weight

Intent

Thes e de vice s are de signe d to limit the current a nd voltag e

co nducte d through a device's po we r or signa l wiring. This

limitation prevents s horting and a rcing of the wires o r de vice ,

thus preventing ignition of the surrounding atmosphere.

They a re com monly used for protec tion of instruments that

ope rate at extremely low powe r levels and are suitable for

expos ure to the environment.

Advantages

The Only Protec tion Allow ed for Zone 0

Eliminate s P os sibility of Explos ion No Hot Permits

Req uires Low Maintena nce No S pecial Ca bles

Idea l for Low-Pow er Device s Limits Energy to Device

Disadvantages

Req uires Doc umentation of I.S. C ircuits a nd Insta llation

Ca n be Used Only With Low-P owe r Device s

In t r ins ic Sa fe ty B arr ie rs




Advantages

Reduces Heat Build up

Inhibits Metal Corrosion

Requires Low Maintenance

Increa se s Equipment Long evity

No S pec ial Enclosures Req uired

Allows Fast Acc es s to Equipment

Red uces Moisture &Dust B uild up

Red uces Clas sifica tion Within the Enclosure

Continuous S ystem Sta tus Indication

P rotects Enclosures up to 450 ft3

Allows use of any Enclosure S hape

Co st of Protec tion per ft3DecreasesWith Enclosure Size

Disadvantages

Contains Moving Parts

Req uires Instrument Air S upply

S ome S ystems Req uire Electronics

Hot Pe rmits Req uired

Pe p p e r l+Fu c h s B e b c o EPS

Purg e and Pre ssur iza t ion is the onlyt e c h n o lo g y t ha t m e e t s t he d e m a n d f o r

g e n e r a l p u r p o s e e q u ip m e n t w it h s ta n d a r denc losure s ins ide haza rdous loc a t ions

Intent

P ep p erl+ Fu c h s B eb c o E P S Divis ion Products are

designed to supply one or more protected enclosures witha clea n instrument air or inert ga s. This proc es s removes

flammable gases or prevents the accumulation of ignitable

dus ts w ithin the protecte d e nclosure(s). This m ethod of

protection is no t limited by the q uantity, co nfig uration, powe r

requireme nts, or loc ation of the protec ted e q uipment. These

sys tems a re commo nly used for all ap plica tions involving ba sic

electronics, electrical equipment, motors and switchgear.

In ad dition these systems ca n also meet the dema nds of

rack mounted instrumentation, vide o displays, program ma blecontrollers, computers, printers, recorders, measurement,

ga s a nalyzers a nd c alibration eq uipment.

One of the bes t benefits is the slow but continuous flow

of protec tive ga s, which ca n be spe cifica lly used to eliminate

prob lems like heat, mo isture, dust a nd c orros ion. And unlike

explosion proof enc los ures , failure of a P eppe rl+ Fuchs

Bebco Enclosure Protection System does not create an

immediate danger.

En c lo s u re Pro te c t io n S ys te m s


4/16


T4

STUD

YGUIDE


D e fin in g H a z a r d o u s Ar e a s

Hazardous Area Definition

Haza rdous (class ifi ed ) loca t ions a re those area s in

an industrial complex where the atmosphere containsflammable concentrations of gases or vapors by leakage,

or ignitable conc entrations of dusts or fibers by s uspens ion

or dispersion.

The Nat ional Fire Protection Association

The Na tional Fire P rotec tion Ass oc iation (NFPA), forme d

in 1896, is a nonprofit organization devoted to fire safety

standards and codes. It currently retains over 40,000

memb ers who wo rk to determine sa fe prac tice s a nd esta blish

sta nda rds for all a reas o f comme rcial, industrial and residential

co nstruc tion. They publish ma ny doc uments including NFPA

70 - better known a s the Nationa l Elec tric C od e a nd NFPA

496 - the doc ument that spec ifies recommended practices

for pres suriza tion a nd p urging.

Area Classification Methods

The NFPA es tab lishes a rea class ific ations using three

factors. Identified as Classes, Groups and Divisions, these

factors are combined to define c onditions of spec ific areas.

Classes are used to define the explosive or ignitable

substa nces that are present in the atmosphere.

Class I - Flam ma ble ga se s or liq uid vapo rsClass II - Ignitable meta l, ca rbon or orga nic dusts

Class III - Ignitable fibrous ma terials

Divisions are used to define the deg ree of ha zard by

dete rmining the explosive o r ignitable s ubsta nce's

expected concentration in the atmosphere.

Division 1 - C ontains substa nces undernormal c onditions

Division 2 - C ontains substa nces underabnormal conditions

Important Notes:Division 1 areas must be surrounded by Division 2 areas.

Groups a re used to defi ne substa nces by rating their

explosive or ignitable nature, in relation to other known

substances .

TYPICAL CLASS I SUBSTANCES

Group A - Ace tylene

Group B - Hydrog en or > 30% Hydrog en by Volume

Group C - Ethyl Ether &Ethylene

Group D - Ace tone, Ammonia, Be nzene &Ga so line

TYPICAL CLASS II SUBSTANCES

Group E - Aluminum, Mag nesium &Alloys

Group F - Ca rbon, Coke &Coal

Group G - Flour, G rain, Woo d, P lastic &Chem ica ls

Zones are used to defi ne the deg ree of haza rd byde termining the e xplos ive or ignitable sub sta nce's

expected conc entration in the a tmosphere.

Zone 0 - Conta ins substa nces undernormal c ond itions (Co ntinuously)

Zone 1 - Conta ins substa nces undernorma l co nditions (Intermittently)

Zone 2 - Conta ins substa nces underabnormal conditions

Today's mod ern refineries and manufacturing comp lexesoften contain b oth flammable g ases and ignitab le dusts,making area classification of Division 1 and Division 2locations an important b ut tricky task.

C lass Rat ings

Gro up Rat ings

D ivision Ra ting s

Zone Rat ings




How can the equipment be accessed?

Equipment mounted in the protected enclos ure ca n

be a cc ess ed if the area is known to be nonhaza rdous,

or if all power to the protected equipment has been

de-energized. In other words , internal equipment

should be treated as if located in an explosion proofenclosure. However, a cooling period may be required

before ac ces sing hot compo nents, such as transformers

or variable speed drives, which would otherwise be

unacceptable for use in the hazardous location.

Equipment mounted through the surfac e o f a

protected enc losure may req uire a s ea led a cc ess doo r

if the equipment is not suitable for exposure to the

surrounding atmosphere. Advanced pressurization

systems, like Pe pperl+ Fuchs B ebc o Rapid ExchangeTM

Purging Systems can maintain a positive pressure, by

increasing the flow of protective ga s w hile the a cc ess

door is open.

What is purging?

P urging is the proc es s of supplying enc los ures w ith compress ed

air or inert ga s a t the prope r flow a nd press ure in order to red uce the

haz ardo us ga s inside the enc los ure to a sa fe level. Pres suriza tion

is the process of bringing compressed air or inert gas within an

enclosure to a press ure w here there is no ingress of haza rdous ga sse sor comb ustible ga s. B oth purging a nd press uriza tion a re req uired in a

Clas s I, ga s a tmosphe re. Only press uriza tion is required in a C las s II,

dust atmos phere.

What is used to purge/pressurize?

The most commo n and prac tica l protective gas is compressed

instrument quality air that contains no more than trace amounts

of combustible vapor. Inert gases, such as nitrogen or argon are

ac ce ptab le. Although they a re usually expens ive and imprac tica l,

they may be required for some g as ana lysis applica tions.

What is the pressure requirement?

Most purging a pplica tions req uire a minimum enc losure press ureof 0.10 inches (2.5 mm) of water. One psi is equal to 27.7 inches

of wa ter. In som e circums tanc es , a minimum enclosure press ure

of 0.50 inches (12.7 mm) of water is required to protect against

ignitable dust. But in all cases, a higher enclosure pressure

should be ma intained to create a rea so nab le sa fety factor. In rare

circumsta nces , enclosure pressures a s high a s 2.5 inches (63.5 mm)

of wa ter may be req uired to offset sudd en atmos pheric press ure

fluctuations, such as those created near missile launching or

off-sho re drilling p latforms .

How much purging gas is used?

Average protective ga s cons umption during pressuriza tion at a 0.10

inch (2.5 mm) enc los ure press ure s hould fa ll somew here betw een

0.1 to 3.5 s c fh pe r cub ic foo t (2.83 to 99.11 l/hr) of en c los ure volume .However, use w ill depend on the protected enclosure's integrity a nd

normal press ure s etting. Use is a lso depend ent on the q uantity a nd

size of covers a nd do ors a s w ell as d evices which penetrate the

surfac e. Adva nced forms of protection such a s c ooling o r dilution

may require continuous flow rates of 30 to 100 scfm (849.38

to 2831.26 l/m). Purging req uires a much higher flow rate than

press uriza tion, b ut only for a s hort period of time.

What kinds of enclosures can be purged?

Any enc los ure can be purge d, but enclosures fea turing ga sketing

and multiple d oor fas teners a re ide al. Therefore, in the a bs enc e

of offi cia l co nstruction req uirements for purge d e nclos ures,

Peppe rl+ Fuchs Be bco reco mmends enc losures which meet or

excee d the National Elec trica l Manufac turers Ass oc iation rating

of NEMA 4 or NEMA 12. For more information on this subject,

se e pa ge T12.

What kinds of devices can be purged?

Virtually any ba sic electrica l device ca n be purge d, if a ll " live"

or energized components can be isolated from the surrounding

environment. Devices such as push-buttons, relays, timers and

programmable controllers only need to be installed in a sealed

enclos ure. Motors only req uire a tota lly enc los ed housing.

?C o m m o n Q u e s t io n s

In this app lication, a stainless steel enclosure features anaccess door for con trol adjustments and maintenance,along with a very unique audible and visual alarm system.


6/16


T6

STUD

YGUIDE


Purging and Pressurizing Methods

The NFPA a nd ISA de fine se veral tec hniques for

protecting equipment. Most eq uipment req uires only bas ic

press uriza tion in Class II area s o r purging in Class I area s.

Ventilation a nd d ilution a re ad vanc ed protection method s

for heat producing or flamma ble ga s a nalyzing e quipment.

Purging

Common equipment in Class I Areas

As s trictly defi ned by NFPA 496, this m ethod is a sta rt-up

process of Class I area pres surizing w hich removes fla mmab le

vapo rs from a protected enclosure. This is ac co mplished

by exchanging a known volume of protective gas, while

maintaining a minimum positive enclosure pressure of 0.10

inche s (2.5 mm) of w a ter. The 2003 ed ition o f NFPA 496

recomm end s 4 volume excha nge s for all enclos ures a nd 10

volume excha nge s for all motors.

Pressurization

Common equipment in Class I & II Areas

This method prevents the entrance of fla mma ble ga s or

co mbustible dus t into protecte d enc losures. In Class II a reas,

this is accomplished by manually removing any dust and

then ap plying a protective g as supply to maintain a pos itive

enclosure pressure of 0.50 inches (12.7 mm) of water. In

Class I areas, this is acc omplished by " purging" as defined

below, a nd by then maintaining a minimum pos itive enc losure

press ure o f 0.10 inche s (2.5 mm) of wa ter. P owe r ca n then

be applied to the protected equipment under conditionses tab lishe d b y the Division rating.

Ventilation

Hot equipment in Class I & II Areas

This me thod provide s protec tion a s o utlined a bove a nd

also removes or dissipates hea t from e lec trica l devices within

a protec ted enc los ure. This metho d is com monly use d to

co ol eq uipment or reduce enc los ure surface tem peratures.

Ventilation req uires high a ir flow a nd is c ommo nly performed

with blowers for high voltage switchgear devices.

Dilution

Analytical equipment in Class I Areas

This method provide s protection as outlined ab ove and

also co ntinuously removes or dissipates flamma ble gas es

within a protected enc los ure. Dilution ma y req uire the use of

nitrogen to b lanket the enc losure. Otherwise, a higher flow

of instrument a ir w ill likely b e req uired.

N FPA & ISA De s ign S tanda rdsPressurization Standards

Co mmittee S P12 of the Instrument S oc iety of America

(IS A) es tab lished the first Des ign S tand ard in 1966, entitled

" IS A s12.4 - Instrument P urging For Red uction Of Ha za rdous

Area Cla ss ifica tion." In 1967, the NFPA Tec hnica l Com mittee

on Elec trica l Equipment in Che mical Atmos pheres e sta blishedrecommended practices, entitled "NFPA 496 - Purged and

P ressurized Enclos ures for Elec trica l Eq uipment." S ince

then, the NFPA has expanded their document by adding

recom mend ations for enc losure ventilation a nd d ilution.

The NFPA do cume nt is the America n stand ard for de sign,

ma rking a nd performanc e of enclosures and press uriza tion

sys tems. The IS A do cument ad dress es c onstruct ion,

insta lla t ion and test ing of protected enclosures and

pressurization systems.

Pressurization "Types"

The NFPA and ISA de fine " Types" of press uriza tion bas ed

on the Division rating of a ha za rdous loca tion a nd elec trica l

ratings of the protected eq uipment. Ge neral purpose and

Division 2 rated electrica l eq uipment req uire different mea ns

of protection, depe nding on their loc ation.

Type "X"

Protects general purpose equipment in Division 1 Areas

This system red uces the clas sifica tion within protected

enc los ures from Division 1 to nonha za rdous. It is req uired to

automatically control electrical power to all protected

equipment.

Type "Y"

Protects Division 2 rated equipment in Division 1 Areas


enclosures from Division 1 to Division 2. All protected

equipment must be rated for Division 2. Automatic power

co ntrol disc onnec ts a re not req uired, but visual and /or audible

a larms m ust be initiated whe n there is loss of pressure.

Type "Z"Protects general purpose equipment in Division 2 Areas


enc los ures from D ivision 2 to nonc las sified . Automatic pow er

co ntrol disc onnec ts a re not req uired, but visual and /or audible

a larms m ust be initiated whe n there is loss of pressure.




Pre ssur iza t ion S ys te m D e s igns

These pressurization system diagrams represent the basicdesigns of modern pneumatic systems.

There a re four prima ry fac tors tha t de termine w hich purge

sys tem is app ropriate for your applica tion:

Classifica tion of the area.

Ratings of the eq uipment inside the enclosure.

Enclos ure size, pos ition of do ors, windows a nd

any ac cess ories .

Po we r requirement to the enclosure (type X system s).

Area Classification

The area clas sifica tion determines the type of purge system

needed. For Division 1 areas, the equipment inside the

enc los ure d etermines whethe r a Type X sys tem (equipment

rated for gene ral-purpose ) or a Type Y sys tem (equipment

rated for Division 2) ca n be us ed .

Equipment Ratings

The rating on the eq uipment inside the enclosure be co mes

important in evaluating which purge system to use in a

Division 1 a rea. If the Division 1 a rea c onta ins a t leas t one

ge neral-purpos e c ompo nent, a Type X system is req uired.

If all devices in the enclosure are rated for Division 2, then

a Type Y system c an b e used . Sp ec ial cond itions e xist for

enclosures such as ga s ana lyzers and chromatographs that

co ntain a fla mma ble ga s. Re fer to NFPA 496 2003 for more

information.

Enclosure Size

The size of the enclosure de termines the size of the purge

system. How the sys tem is mo unted depend s on the pos ition

of doors, windows a nd cab le entrance s.

Power Requirement

For Type X sys tems, the co ntrol unit operates the pow er

disc onnec t to the enc los ure. If the pow er req uirement for the

enclosure exceeds the contact ratings on the control unit,

a c ontrol relay mus t be a dd ed. If the co ntrol relay is loc ated

in the haza rdous area, it must be rated for that ha zardous

location. As power increases inside the enclosure, high

tempera tures bec ome a problem. Refer to NFPA 496 2003for more information.

For Type Y a nd Z purge system s, aud ible ala rms or visua l

indicators must be used to notify operators that pressure

inside the enclosure is below the NFPA minimum. Ala rms are connec ted directly to the enclosure and monitor

the differential air press ure be twe en the enc los ure a nd the

environment outside it. These alarms are a ctivate d b y the

reduction in flow or press ure w ithin the protec tive enc los ure

and have a direct connection to the enclosure, eliminating

the need for an alarm on the protective g as supply.

The alarm must be loc ate d where the ope rator ca n

se e it ea sily.

The alarm must take its mea surement from the

enc los ure only.

Alarms located in the haza rdous area must be rated

for the area .

Valves ca nnot be connec ted betwee n the alarm and

the enclosure.

C ho o s ing a S ys te m Re q uire m e nts fo r Ala rm s

OP TIONAL PRES SU RE

RELIEF DEVICE

PRESSURE

INDIC ATOR

OP TIONAL

ALARM

OR

POWER

C UT-OFF

S WITCH

P ROTECTIVE

GAS SUP PLY

PRESSURE

REG ULATOR

P ROTECTED

ENCLOSURE

BALL

VALVE

NEEDLE

VALVE


RELIEF DEVICE

PRESSURE

INDIC ATOR

OP TIONAL

ALARM

OR

PO WER

CUT-OFF

S WITC H

P ROTECTIVE

GAS SUP PLY

P ROTEC TED

ENCLOSURE

PRESSURE

REG ULATOR


8/16T8

DES

IGNGUIDE



Typic a l Enc los ure C o nne c t io ns

General Recommendations

1. The press urizing s ystem s hould be loc ate d immediately

adjacent to the protected enclosure(s) when possible.

2. The press urizing s ystem sho uld b e installed at e ye level,

in a prominent location, for convenient viewing.

3. No valves s hould be insta lled b etw een the press urizing

system and the protected enclosure(s).

4. The reference c onnec tion from the protected enclosure(s)

should be installed in a location which is not directly

affected by air flow through the protected enclosure(s).

5. All tubing, piping and c onnec tion fittings sho uld be s uita ble

for the loca tion in which they a re insta lled and sho uld b e

protected against mechanical damage.

Class I Area Recommendat ions

If fla mma ble ga se s are lighter than air, the supp ly

connec tion to ea ch enc losure should enter near a bottom

co rner and the co nnection for an optional vent or piping to

the next protected enclosure should exit near an extreme

oppo site top corner.

If flammab le ga ses a re heavier than air, connections

should be reversed.

Multiple Enclosure Recommendations

1. Protected enclosures should be connected from the

sma lles t to large st enc los ure in se ries .

2. Connections should be sized to allow proper operation

of the pressuriza tion sys tem.

3. Co nduit or wirewa ys may be utilized a s protected enc losures

or as connec tions b etween protected e nclosures.*

These Clas s I a rea recomme nda t ions exceed the

req uireme nts o f NFPA 496. They a re prese nted b y

Pe pperl+ Fuchs Beb co a s a method to enhance the removal

of flamma ble gas es by the use of g ravity.

These C las s I a rea rec omme nda tions only ap ply to

enclosure volumes exceeding two cubic feet.

Single Enclosures

M ult ip le Enc losure s

REFERENC E TO

ALARM, INDIC ATOR

OR C UT-OFF S WITC H

OPTIONAL PRES S URE

RELIEF DEVICE

SUP PLY FROM

ENCLOSURE

PRESSURIZING

SYSTEM

P ROTECTED

ENCLOSURE

4. All pressurized conduit and wireways should be sized to

allow proper protective gas flow through the protected

enclosures.

* The NFPA reco gnizes the us e of electrica l co nduit or

wirewa ys a s a part of an " ap proved system" . The NFPA

term "approved system" refers to a complete purged

assembly that has been approved by the authority

having jurisdiction.

REFERENC E TO

ALARM, INDIC ATOR

OR C UT-OFF S WITC H

SUP PLY FROM

ENCLOSURE

PRESSURIZING

S YSTEM


RELIEF DEVICE

P ROTECTED

ENCLOSURE

INTERCONNECTINGP IP E OR WIREWAY




Ind ic a tors , Ala rm s & C utof fs

The disc onnec t sw itch immed iately cuts off powe r to the

enclos ure w hen press ure d rops be low a s afe level. This

sw itching is required for Type X sys tems but c a n used inType Y a nd Z s ystem s.

There are exce ptions to the disc onne ct rule for Type X

systems, bec ause in some instances, a power loss represents

a g reater ha za rd than operating the sys tem under low pres sure.

An alarm is a cc eptab le in those circums tanc es , but only for

a short time and special requirements may be necessary.

Requirements for disconnect switches:

Must be ac tuated by either the protec tive ga s flow rate

or the differential pressure inside the enclosure.

Must be a pproved for its loc ation.

No valves shall be connec ted betwee n the disco nnect

switch and the enclosure.

S hall take its signa l from the protec ted enc los ure and

sha ll not be installed b etw een the enc los ure a nd the

protec tive g a s s upply. Refer to NFPA 496, se c tion 4.10.1

for more information.

Indica tors can be used whe n there is an alarm for the

protective gas supply and the enclosure is isolated with a

valve immed iately a djace nt to the e nclosure. The va lve musthave an a ppropriate w a rning labe l a nd ca n be used only for

the enclosure. Refer to NFPA 496 2003, section 4.8.4 for

more information.

The indica tor must be loc ated whe re the operator can

se e it eas ily.

The indica tor must show either press ure or flow.

The indica tor ca nnot be insta lled b etwe en the enc los ure

and protective gas supply.

No valves shall be co nnected betw een the indica tor and

the enclosure.

The protec tive ga s supply shall have an a la rm loca ted in a

constantly attended area and fulfill requirements in 4.3.2.

Single Enclosure Applications Multiple Enclosure Applications

Upstream Alarm Application Downstream Alarm Application

Re quire m e nts fo r Ind ic a to rs Re quire m e nts fo r Dis c onne c ts

P RO TEC TIVE

GAS SUP PLY

P ROTECTED

ENCLOSURE

INDIC ATOR , ALARM

OR CU TOFF S WITCH

P ROTECTIVE

GAS SUP PLY

P ROTECTED

ENCLOSURES

INDICATOR, ALARM

OR CU TOFF S WITCH

P ROTECTIVE

GAS SUP PLY

ALARMVALVE P ROTECTED

ENCLOSURE(S)

P OS ITION NOT CR ITICAL

P ROTEC TED

ENCLOSURE(S)

P RO TEC TIVE

GAS SUP PLY

ALARM VALVE

P OS ITION &LABEL CR ITICAL

(S EE ABOVE)

Pro te c te d En c lo s u reDe v ice De ta ils

Pro te c t iv e Ga sSupply Alarm Detai ls


10/16T10

DES

IGNGUIDE



In a gene ral se nse, protec ted enclosures should be wired

similar to explos ion proo f enclos ures, in ac co rda nce w ith Article

500 of the National Electric Code - NFPA 70.

Single conductor wiring should be placed in rigid metal

co nduit, sea l-flex conduit or other med iums a pproved for use

in the ha za rdous loca tion s urrounding the protected enclosure.

Additionally, NFPA 496requires the use o f approved se als onall pres surized enclosure co nduit wiring entries , in acc orda nce

with NFPA 70. Furthermore, the use of an approved seal issimply the most practical way to prevent excessive leakage

through c onduit connections.

However, while explosion proof enclosures require conduit

seals on all cable entries, in accordance with NFPA 70. Othermethods of sea led ca ble entries that a re suitable for haza rdous

loca tions ca n be used, such as c ompression glands.

In co nclusion, there a re two prima ry go als. First, the insta llersho uld ensure that all as so ciated w iring a nd ca ble is protected

by pressurization or other means, such as explosion proof

conduit or intrinsic safety barriers. Secondly, the installer

should e nsure that a ll asso ciated c onduit and wirewa ys a re

sealed to conserve protective gas, unless they are used to

supply protec tive ga s to other enclosures or device s.

Sections 4.11 & 6.3of the 2003 NFPA 496 req uire ma rking son a ll protected e nclosures with a " permanent label," loc ated in

a " prominent loc ation," nea r all do ors and ac ce ss covers. The

lab els must include the following o r eq uivalent statem ents:

Class I Locations:" WARNING - PRESSURIZED ENCLOSURE"

" This enclosure sha ll not be op ened unless the area is known to be free

of fla mmab le ma terials o r unless all devices have be en de -energized."

Class II Locations:" WARNING - PRESSURIZED ENCLOSURE"

" Pow er shall not be restored after the enclosure has been o pened until

co mbustible dust have been removed a nd the enclosure repress urized."

Section 5.3 requires the following or equivalent statementin addition to the statement required by Section 4.11 above.

" Po wer sha ll not be restored a fter enclosure has b een ope ned until

enclos ure ha s b een purged for _ minutes a t a flow rate of _."

ANote to Section 5.3pe rmits the use of minimum pres surein place of flow rate if the pressure can positively indicate a

known flow rate.

An Exception to Section 5.3allow s plac eme nt of the sta rt-upinstructions on the p ressurizing sys tem, if they a re referenced

by the permane nt la bel on the protec ted enc los ure.

In ad dit ion, a l l permane nt la bels must include three

other ma rkings :

Section 4.11:Clas s, G roup and Division of surrounding area

Section 4.11:NFPA pres s uriza tion Type X, Y, o r Z

Section 4.11:TCode (temperature identification number):se e NFPA 70, The Na tiona l Elect ric C od e, Article 500,

Ta ble 500-3(d)

Exception No. 1a llows omission of the TCo de ma rking if thehottest temperature do es not exceed 100 C.

Exception No. 2 a llows omission of the T Cod e ma rkingfor equipment which is marked for specific use in gas or dust

atmos pheres a nd doe s not exceed 80% of the flammab le or

ignitable a tmos phere's ignition te mperature.

Enc los ure M a rk ing & W ir ing

E nc lo s ur e M a r k in g R e q uir e m e n ts Typ ic a l En c lo s ur e W ir in g M e t ho d s

Spe c ia l M ark ing Requirem ents

Exceptions to S ec tion 4.5 require enclosures to be ma rked w iththe following o r equivalent statem ent if they house eq uipment w hich

ca n exceed the T-Co de rating, to c omply with Se ction 4.11.4:

"WARNING - HOT INTERNAL PARTS"" This enc losure sha ll not be opened unless the area is known to be

nonflamma ble or unless all equipment within has been

de -energized fo r _ minutes ."

An Exception to Sec tion 4.8.2 permits the use of an indica tor on

the protected enclosure if all isolation valves are adjacent to the

enclosure (see page 11) and marked to comply with Section 4.11.5:

"WARNING - PROTECTIVE GAS SUPPLY VALVE"" This valve must b e kept open unless the a rea is known to be

nonflammable or unless all equipment within the protectedenclosure is de-energized."

Typical EnclosureW iring Co nnec tion

P ROTECTED

ENCLOSURE

OR DEVICE

EXPLOSION

PROOF DEVICE

INTRINS ICALLY

SAFE OR FIBER

OP TIC DEVICE

INTRINS ICALLY

SAFE OR FIBER

OP TIC DEVICE

INDEP ENDE NTLY

PRESSURIZED

DEVICE

ADJ ACENT

PRESSURIZED

DEVICE

PRESSURIZED

RAC EWAY

CONDUITSEAL

CONDUITSEAL

CONDUITSEAL

G LAND FITTINGCABLE




Start- Up Conditions

P rotec tion Method: Type " X" Press uriza tion S ystemPo we ring Method: Automatic Po we r Co ntrol Unit or

Local Disconnect SwitchSys tem Sta tus: Protected Equipment De-energized

Alarm S ys tem a nd Air Supply On

Operating Procedures

1. Remove haz ardous s ubstanc e from the protectedenclosure. A vacuum device is the preferred tool fordus t remova l.

2. Che ck ope ration of e nclosure press ure relief de vice(if utilized ) and se al the protected enc los ure.

3. Press urize the protected e nclosure to set and ma intaina p os itive pres sure o f 0.50 inc hes (12.7 mm) of w a ter.

4. Sys tem will ap ply power automa tica lly whe n pressure isset a nd ma intained a t a pos itive pres sure of 0.50 inches

(12.7 mm ) of w a ter.5. Los s of press uriza tion must a utomatica lly de -energize

protected eq uipment pow er immed iately.Exception:Automatic power control is not required ifthe enclosure is de signed to prevent the entranc e ofdust and the pressurization system activates an audibleor visua l alarm in a co nsta ntly attend ed loc ation.

6. Eq uipment that ma y overloa d or overheat, such a smotors o r trans formers, require therma l overloa d c utoffswitches or a larms.

B a s ic O p e r a t in g Pro c e d u r e s

Start- Up Conditions

P rotection Method : Type " X" P urge /P ress uriza tion S ystemPo we ring Method: Automatic Po we r Co ntrol UnitSys tem Sta tus: Protected Equipment De-energized

Alarm S ys tem a nd Air Supply On


1. Che ck ope ration of enc los ure press ure relief device(if utilized) and seal the protected enclosure.

2. Pres surize the protec ted enc los ure to set and m aintain aminimum po sitive pres sure o f 0.10 inches (2.5 mm) of wa ter.

3. Exchange the recommend ed volumes of purging ga s.

4. S ystem w ill de ny powe r automatica lly until recom mend edvolume exchange is c omplete a nd pressure is s et andmaintained at a minimum positive pressure of 0.10 inches(2.5 mm) of wa ter.

5. Loss of pressuriza tion must a utomatica lly de -energizeprotected eq uipment pow er immed iately.Exception:P owe r may be ma intained for a s hort periodif immed iate loss of powe r would result in a mo re haza rdouscondition and if the system activates both audible andvisual alarms in a constantly attended location.

6. Equipment that may overloa d or overhea t, such as m otorsor tra nsformers, req uire therma l overloa d c utoff switchesor alarms.

Start-Up Conditions

P rotec tion Method : Type "Z" Purge/Press urization S ystemPo wering Method: Loca l Disc onnec t S witchS ystem S tatus: P rotec ted Equipment De-energized Alarm S yste m a nd Air S upply On


1. Chec k operation of enc los ure pres sure relief de vice(if utilized) and seal the protected enclosure.

2. Pressurize the protected enclosure to set and maintain aminimum pos itive press ure of 0.10 inches (2.5 mm) of wa ter.

3. Exchang e the recommended volumes of purging ga s.

Exception:Pow er may be e nergized immed iately ifthe protected enclosure atmosphere is known to benonflammable.

4. Energize the protected eq uipment po we r manually w itha disconnect s witch o r breaker rated for the haza rdouslocation.

5. Loss of press uriza tion req uires immediate a ttention o rthe manua l de -energizing of protected eq uipment pow er.

6. Excessively hot equipment must be isolated in a separateprotected e nclosure, unles s the enc los ure is markedwith a warning which indicates a required cool-downtime period b efore a cc ess .

Start-Up Conditions

Protec tion Method: Type " Z" Pres suriza tion S ystemPo wering Method: Loca l Disc onnec t S witchS ystem S tatus: P rotec ted Equipment De-energized Alarm S ys tem a nd Air S upply On


1. Remove haz ardous s ubstance from the protectedenclosure. A vacuum device is the preferred tool fordust remova l.

2. Chec k operation of enc los ure pres sure relief de vice(if utilized) and seal the protected enclosure.

3. Press urize the protected enclosure to set a nd ma intaina p os itive pres sure o f 0.50 inch es (12.7 mm) of w a ter.

4. Energize the protected eq uipment po we r manually w itha disconnect s witch o r breaker rated for the haza rdouslocation.

5. Loss of press uriza tion req uires immediate a ttention o rthe manua l de -energizing of protected eq uipment pow er.

6. Excessively hot equipment must be isolated in a separateprotected e nclosure, unles s the enc los ure is markedwith a warning which indicates a required cool-downtime period b efore a cc ess .

C la s s II, D iv. 1 P re s s ur iz a t io n C la s s II, D iv. 2 P r e s s ur iz a t io n

Class I, Div. 1Purge/Pressurizat ion

C la ss I, Div. 2Purge/Pressurizat ion


12/16T12

APPLICATIONGUIDE



Enc los ure D e s ig n Co ns ide ra t ions

1. All window s should be shatterproof and sized as s ma llas poss ible.

2. All NFPA 496 req uired m a rkings s hould be plac ed o n ornea r all do ors a nd co vers, and s hould be e a sily visible.

3. The enclosure should withstand an internal pres sure offive (5) inches of wa ter without sus taining p ermane ntde formation a nd resist a ll corros ive elements in thesurrounding atmosphere.

4. All lightw eight objec ts in the enclosure, such a s pa peror insulation, s hould b e fi rmly s ec ured .

5. The enclosure should be c onstructed from materialssuc h as meta l or polycarbo nate to meet NEMA 4 or 12performanc e requirements , but doe s not require 3rdparty approval.

6. The insta lla tion of obstructions or other barriers which blockor imped e the flow of protective ga s s hould be avoided.

7. The creation of a ir poc kets or other a reas w hich trapflamma ble g as es within the enclosure s hould b e a voided .

8. The enclosure should be loc ate d in an area whereimpact hazards are minimal.

9. A press ure relief device sho uld be us ed if it is req uired toprotect the enc los ure a ga inst press urization system co ntrolfailure or to a llow proper purging s ystem ope ration.

10. If the enclosure is non-metallic and contains equipmentwhich utilizes or switches powe r loa ds greater than2500 VA, it sho uld b e c ons tructed from s ubs ta ntiallynon-comb ustible materials, such a s ma terials des ignedto mee t or exc ee d ANSI/UL94 rating s o f 94 V-0 or 94 5V.

11. The enc los ure s hould ha ve no s urfac e a rea tha texceed s 80% of the flamma ble or ignitab le s ubstanc e'sauto-ignition temperature.

12. If the enc los ure is protec ted by a Type X S ystem a ndca n be op ened without the use o f a tool or key, thedo or should be e q uipped with a Division 1 rate d pow erinterloc k switch to d e-energize a ll equipment that is notsuitable for Division 1 a reas .

1. The tota l volume of a ll pres surized enc losures , devicesand w irewa ys should be c onsidered.

2. All enclosure, d evice and wirewa y volumes sho uld b eca lculated w ithout cons ideration of internally co nsumedspace. Exceptions: motor starters, rotors, field coils, etc.

3. Cubical device volumes should be calculated as follows:

Height x Width x Dep th - in inches 1728 = ft3

- in feet = ft3

4. Cylindrica l device volumes m ay b e ca lculated as follow s:

r2x Cy linder Length - in inches 1728 = ft3

- in feet = ft3

1. All pres sure relief devices s hould be de signe d to minimizeair leakage, unless intended for dilution or ventilation.

2. All press ure relief devices s hould be c ons tructed fromflame, shatter and ignition proof substances. In addition,they should b e de signed to prevent the esca pe of spa rksa nd burning ma terials.

1. All interna l enc losures (within the protec ted e nclos ure)should be p rotected by one o f the follow ing me ans , if thefree volume of the internal enc los ure exc eed s 1.22 cubic

inches (20 cm3).2. Internal enclosures s hould be ventilated on the top and

bottom sides with at leas t one (1) sq uare inch (6.5 cm3) ofope ning fo r eac h four hundred (400) cub ic inches (6560 cm3)of volume within the internal protected enclosure, with aminimum s ize of o ne q ua rter (1/4) inch d iame ter (6.3 mm); or,

3. Adjace nt and internal enc los ures s hould be purged inse ries w ith the protec ted enc los ure or be purgedse pa rately; or,

4. Equipment within ad jac ent and internal enclosures shouldbe protected by other means; e.g. explosion proofenclos ures , hermetically se aled housings or intrinsicsafety barriers.

Captive screw and cage nutassemb lies can be used to p rovide

multiple po int fasteners, and improveenclosure app earance and pressure seals.

Some enclosuremanufacturersutilize clamp ingfasteners to meetTYPE 4 performancerequirements.

All design considerations presented on thispage are intended for basic applications only.

P ro te c te d Enc lo s ure s Ad ja c e nt & In te rna l Enc lo s ure s

Pre s s u re Re lie f D e v ic e s

Typic a l Fa ste ninga n d G a s k e t in g M e t h o d s

Ca lcu la t ion o f Enc losurea n d De v ic e Vo lu m e s




This enclosure features a removablegasketing trim, which features a highprofile w ith excep tional memory.

Most cus tom and s tand a rd enclosures a re suitable for purging a nd press uriza tion if req uirements mee t or exce ed Type 4 or

requirements. However, the use of multiple door fasteners provides a well-sealed enclosure that allows conservation of protective ga

In this application, a custom b uilt stainlessteel enclo sure is fitted wit h severalPepperl+Fuchs Bebco products, includina Rapid ExchangeTMPurging System, andan Enclosure Protection Vent.

In this app lication, a dual p ressurization systemis mounted abo ve two identical devices thatare separately protec ted to allow independentaccess. Both devices feature TYPE 4 cases,which makes them suitable for purging as is.

Both assemblies

pictured aresuitable forClass I,Group C & D,Division 2hazardouslocations.

Unlike previous subjec ts, these cons ide rations are ba se d

mainly upon commo n sense and sound e ngineering prac tices ,

bec aus e while the NFPA and IS A have ad dress ed ma ny other

fac tors, d evice use is m os tly unregulated. Therefore, w hile

the following considerations are based on applications that

have been installed and proven, many are presented in the

ab senc e of standa rds. In add ition, this sec tion does not ad dress

ana lytical eq uipment. Re memb er, the ultima te respo nsibility

for insta llation a pproval, reg a rdles s of c urrent reg ulations, lies

with the a uthority ha ving jurisdiction.

D e v ic e Use C ons ide ra t ions

P r e f a c e

Controllers, Indicators & Recorders

Tod ay's pa nel mounted instrumenta tion is a lmos t strictly

elec tronic. The protruding fac e of these instruments norma lly

contains LEDs, LCDs and incandescent or florescent lights.

Therefore, it is extremely importa nt to isolate a ll instrumenta tion

from the surrounding atmosphere, unless the face is sealed

and all electronics are properly ventilated to the protected

enclosure.

The use of devices tha t penetrate the surfac e of a protectedenclosure must be carefully scrutinized. Protruding devices

will likely c onta in elec trica l comp onents that co uld either be

exposed to the hazardous location or be isolated from the

flow o f protective gas . Conventional wisdom sug ges ts that a

protruding device should be acceptable if it is (1) explosion

proof, (2) intrinsica lly s afe, (3) proven to emit insuffic ient ene rgy

to ig nite the surrounding a tmos phere (applica ble for Division 2

loca tions only), (4) co nstruc ted s o tha t all elec tronics w ithin its

fac e a re suitab ly sea led from the surrounding environment and

properly ventilated to the protected enclosure, o r (5) iso lated

from the surrounding a tmosphere by a sea led w indow o r ac ces s

do or that is properly ventilated to the protected enclosure.

Prot rud ing De v ice s


14/16T14

APPLICATIONGUIDE



Motors

Tota lly enc lose d moto rs, with NEMA rating s suc h a s TENV,

TEFC or TEAO, a re be st suited for press uriza tion, b ut the

following factors should also be considered. (1) All motors

should have suffic ient ca vities and openings to pe rmit the flow

of protective ga s a round the w indings . (2) The ga s c onnec tions

for the supply and return of protective g as should be loca ted

at extreme o ppos ite ends of the motor. (3) Pe ripheral device s

such as electrical connections, optical encoders and brakes

may require a separate housing, purged in series with the

motor. (4) Pressure within the motor should not exceed

the minimum requirement ,

bec ause exces sive pres sure

will force grease out of

sha ft bea ring se a ls. Finally,

Class I motors require 10

volume exchang es be fore

energizing power.

D e v ic e Use C ons ide ra t ions

Peripheral Devices & Instrument Keypads

Tec hnica lly sp ea king, it is impos sible to pres surize ma ny

peripheral device s, e ven if they a re Type 4 rate d. First, m os t

ba r coders and wa nds feature no internal cavity. Sec ondly,

the membrane assembly of most peripheral keyboards

iso lates key contac ts from the protected ga s. Therefore,all peripheral devices not s uitab le for pres suriza tion s hould

be protected by intrinsic safety barriers. Furthermore, the

ba rriers a nd a ll intrinsic s afe wiring should b e me cha nica lly

isolated from all other devices and wiring in the protected

enclosure. Most peripheral devices can be easily modified

with intrinsic safety barriers, however, its very impractical to

modify pa nel mounted instrument keypad s. Acc epting this fac t,

such instruments should be located b ehind a se aled ac ces s

door that is properly ventilated to the protected enclosure.

NOTE:S ome e nd use rs allow the us e of these d evice s in Division2 areas without barriers, assuming the normally low energy

to these devices will not ignite the surrounding a tmos phere.

However, the pos sibility of a ground fault or current overloa d

will always exist without barrier protection.

Pilot Lights

A pilot light is norma lly unacc epta ble unles s rated for use

in the haz ardo us loca tion. However, some a uthorities ha ving

jurisdiction permit the use of LED clusters and VDC bulbs,

after determining they have insufficient power to ignite thesurrounding atmosphere. Other concerns should include

impa ct resistanc e and potential pow er diss ipation, unles s the

pilot light is protected as noted.

Relays, timers, c ounters, pow er supplies a nd o ther internally

mounted e lectrica l eq uipment sho uld be ventila ted or protec ted

in ac co rdanc e with the cons ide rations for adjace nt and internal

enc losures (see pa g e T12). In ad dition a ll de vice s sho uld

not exceed 80% of the flammable or ignitable substance

auto-ignition tem perature, unles s (1) it c an be show n by testing

that the device will not ignite the surrounding atmosphere,(2) the device is enc los ed in a he rmetica lly se aled cha mbe r,

(3) the protected enclosure is equipped with a temperature

warning nameplate, or (4) the device is separately housed

and pressurized.

Printers

In ad dition to co nside rations for internal eq uipme nt, sp ec ial

attention must be given to printing devices. First, in order

to dispense the printed material, protected enclosures may

req uire a "c hute" to g uide it outward. S econd, a "s lot" must be

inco rporated to dispe nse the p rinted m a teria l, while minimizing

the leakage of protective gas. Finally, if the slot dispenses

printed ma teria l through the top of the protec ted e nclos ure, or

if printed m ate ria l is only dispe nse d pe riod ica lly, the protec tedenclosure may also require a cover or a s ealed a cc ess door to

prevent e nclosure co ntamination.

In terna l De v ice s

Due to the limitations es tab lished ab ove, mos t instrumentswill require isolation through the use of a s ea led a cc es s d oor

(se e pa ge T5). How ever, w hile the instruments a re then norma lly

inac ces sible, some end use rs permit " limited a cc ess" while

maintaining a positive pressure, to perform maintenance,

ca libration and a djustme nt. The proces s of limited a cc es s ma y

be a cco mplished by using P epperl+ Fuchs Beb co Rapid

ExchangeTM Purging Systems. Specia l door labeling or

p u r g i n g s y s t e m a u t o m a t i o n m a y a l s o b e r e q u i r e d .

NOTE: Thes e de signs s hould b e reviewe d by a ll pa rties ,es pec ially the a uthority ha ving jurisd iction, prior to eng ineering

or fabrica tion co mmitments.

Operators

Pa nel mounted operators such as push but tons and

se lecto r sw itch es s hould be Type 4 rated or oil-tight

and should not conta in i l lumina t ion dev ices such as

inca ndesc ent bulbs, unless they are protected a s noted b elow.

NOTE: A majority of end users permit the use of generalpurpose illuminated operators in Division 2 areas, if they are

isolated from impact with guards.




C a m e r a s & M o n it o rs

With increa se d use over the la st de ca de , in areas like se curity

surveillance, thermography and pollution control monitoring, video

equipment can reach into many hazardous areas. Most applications

normally revolve a round mod ifying o r enca sing the existing c am era, b ut

co st a re usually neg ligible.

Reg ardless of their loc ation, displays a nd a nnunciato rs are one of the

simplest devices to protect, simply because they require only limited

ac ce ss . Typical insta llation sa vings may run into thousa nds of do lla rs,

and the eq uipment is protected from a ll eleme nts of the environment.

Disp lays & Annuncia to rs

Ada pting ge neral purpose meters, lights a nd co ntrols for use in a

haza rdous area requires lit t le more than a sea led enclosure, a sea led doo r

for limited ac ce ss , a nd a protection sys tem. In this ap plica tion, intrinsic

sa fety ba rriers a re loc ated within the enclosure (a s afe a rea) and receive

signa ls from the flow rate tra nsmitters loc ated in the nearby pipelines.

Loca l Co ntro l Pa ne ls

Typ ic a l Ap p lic a t io ns


16/16

APPLICATIONGUIDE


Reg a rdless of their purpos e, be it milling, grinding, drilling, wra pping

or stuffing , C NC (Co mputer Numerica lly C ontrolled ) mac hinery ca nnot

typica lly be use d in a ha za rdous loca tion, bec aus e the majority of market

ap plica tions drives mo st ma nufac turers to o nly offer conventiona l de signs.

However, by ca refully exa mining a nd mo difying va rious C NC ma chines,

P+ F Bebc o has sa tisfie d ma ny applica tions, including s ome very unusualneed s, suc h a s the milling of plastic explosives for military a pplica tions

and the stretch wrapping of pallets loaded with bags of highly ignitable dust.

C N C M a c h in e r y

Be ginning with the controls, protection of a filling or we ighing system is

simple. Weigh sc ale platform eq uipment is usua lly ea sy to press urize, o r

ma y be a vaila ble in intrinsica lly sa fe versions. From there, filling eq uipme nt,such a s s olenoids , motors, servos and dribble valves ca n be protected in

a number of w ays . Finally, to c omplete the ap plica tion, o n-site, real-time

printouts of tickets, reports or prod uct labels ca n be obta ined by a dd ing

cus tom-built pres surized enc los ures for the printing eq uipment.

Filling & W e ig hing

Whethe r they are reciproca l motion or multimotion mac hines,

today's advanced robotic machines are going into many hazardous

or toxic a reas . Pe pperl+ Fuchs p roducts a re there too, utilized to allow

robotic equipment to perform tasks such as automotive paint spraying,

silico ne chip production and ca rbon fiber lam ination of ae rospa ce pa rts.

Motors, servos, s ensors a nd on-boa rd e lectronics are ea sily protected

with a combination of intrinsic safety barriers and pressurization, and

in most cases these upgrades require only limited modification of the

original machine.

Robot ics

Typ ic a l Ap p lic a t io ns

purge tech review

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