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SENTRY GS excess flow valves (EFVs) and SENTRY GT thermal cutoff devices (TCOs) have been used effectively worldwide for more than 20 years. In Germany alone, more than 2,250,000 Mertik Maxitrol EFVs (both underground service line and residential installations) are currently in service.

EFV 

with TCO

max. 1 mbar

pressure

drop

In accordance with the IGE/G/5 Edition 2 2012/Gas in Flats.

SENTRY GS Excess Flow Valves and SENTRY GT Thermal Cutoff Devices

  From left to right: SENTRY GS models GS20HH6LCZ and GS20HT6ACZ (with TCO); SENTRY GT models GT20DIA, GT50II and GT25DIA

* DVGW-TRGI 2008 and the DVFG-TRF 2012:German mandatory technical regulation for the planning, construction, modification and servicing of natural gas (TRGI) and liquid gas (TRF) installations.

** Pressure Equipment Directive (97/23/EC): “Directive of the European Parliament and of the council relating to simple pressure vessels.

*** DVGW VP 305-1, edition 12/2007Excerpt of DVGW-TRGI 2008 that prescribe the German standard for excess flow valves in residential installations.

EFV

max. 0.5 mbar

pressure

drop

SENTRY GT SENTRY GT TCOs automatically shut off the gas flow at tem-peratures between 92 °C and 100 °C. At the release tempera-ture, the release mechanism (temperature sensor) unblocks the closing unit, and the closing unit moves into the valve seat resulting in a gas-tight seal. They remain closed up to 925 °C.

These cutoff devices help prevent gas from flowing to down-stream components that may not be resistant to high tem-peratures. When tripped the SENTRY GT allows no more than 30 l/h measured in air to pass through or escape from the device for a period of at least 30 minutes at temperatures up to 650 °C.

SENTRY GT TCOs meet the requirements of:¡ General Gas Guidance IGE/G/5 Edition 2 2012/ Gas in Flats

and multi-dwelling buildingsand are certified according to:¡Pressure Equipment Directive 97/23/EC **¡DIN 3586

SENTRY GS SENTRY GS EFVs for residential installation shut off the gas flow when a predefined closing flow rate is reached. Mertik Maxitrol’s factory adjustment (100 %) provides a precise and reliable closing flow rate. In the nominal flow range, the EFV remains in a stable, open position. SENTRY GS are also avail-able in combination with a thermal cutoff device.

The EFV is installed downstream of the emergency control valve (ECV). If equipped with a by-pass orifice, Sentry GS EFVs reopen after the downstream line has been repaired and re-pressurized.

SENTRY GS EFVs meet the requirements of:¡General Gas Guidance IGE/G/5 Edition 2 2012/Gas in Flats

and multi-dwelling buildings¡German DVGW TRGI 2008 * ¡German DVFG TRF 2012 * and are certified according to:¡Pressure Equipment Directive 97/23/EC **¡German DVGW VP 305-1***

www.mertikmaxitrol.comR

600CWPPN40MS58

600

CWP

PN40

MS58

600

CWP

PN40

MS58

600

CWP

PN40

MS58

600

CWP

PN40

MS58

600

CWP

PN40

MS58

600

CWP

PN40

MS58

600

CWP

PN40

MS58

MODElS / DIMENSIONS

SpECIFICaTIONS (See label attached to SENTRY GT)¡Gases: Suitable for gases according to DIN EN 437¡ambient Temperature: -20 °C to + 80 °C (open) ¡Release Temperature: +100 °C to 8 K¡Nominal pressure: MOP 5 (PN 5)¡allowable leakage: < 30 l/h¡ product Codes: GT20DIa, GT25DIa, GT50II¡Thread Connections: I – Internal thread according to DIN EN 10226-1 / ISO 7-1 (parallel) a – External thread according to DIN EN 10226-1 / ISO 7-1 (conical)

SENTRY GT

600

CWP

PN40

MS58

600

CWP

PN40

MS58

600

CWP

PN40

MS58

RE-OpENING ThE SENTRY GSSENTRY GS for residential installations are normally equip-ped with a by-pass orifice allowing the GS to reopen after the downstream line has been repaired and repressurized. Excess flow valves should be installed directly downstream of the

emergency control valve. Close the emergency control valve downstream to speed resetting of the EFV. When initially in-troducing or restoring the gas supply to the excess flow valve, open the emergency control valve slowly.

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SENTRY GS SpECIFICaTIONS (See label attached to SENTRY GS)¡Gases:  Suitable for gases according to DIN EN 437¡ ambient Temperature: - 20 °C to + 60 °C¡ product Codes: GS20HH6lCZ, GS20HT6aCZ¡ Thread Connections:  a – External thread according to DIN EN 10226-1 / ISO 7-1 (conical) l – Internal thread according to BS746 3/4” (with washer) C – External thread according to BS746

MODElS / DIMENSIONS

* Additional emergency control valve

TypeOrder Code

product Mounting position

Operating pressure Range

pressure Drop

Overflow Volume

Installation Max. Test pressure (in open position)

GS20HH6LCZ EFV horizontal or vertical up-ward (type K)

15 mbar – 100 mbar(1.5 kPa – 10 kPa)

≤ 0.5 mbar (50 Pa)

max. 30 l/hat 100 mbar (10 kPa)

between AECV * and ECV or be-tween ECV and service regulator; downstream of service regulator

1.5 bar(150 kPa)

GS20HT6ACZ EFV with integrated TCO

horizontal or vertical up-ward (type K)

15 mbar – 100 mbar(1.5 kPa – 10 kPa)

≤ 1 mbar(100 Pa)

max. 30 l/hat 100 mbar (10 kPa)

between AECV * and ECV or be-tween ECV and service regulator; downstream of service regulator

1.5 bar(150 kPa)

R

TypeOrder Code

Connections Surface Dimensions [mm]

Weight [kg]

Cert. No.

Inlet Outlet L1 L2

GT20DIA Rp 3/4 R 3/4 blue galvanized 51.0 34.0 32 0.10 CE-0085BN0394

GT25DIA rp 1 r 1 black galvanized 53.8 34.6 41 0.21 CE-0085BN0394

GT50II Rp 2 Rp 2 nickel plated 135.0 - 80 2.60 CE-0085BN0395

Internal Thread External Thread

Wrench Size

Internal Thread

pRESSuRE DROppRESSuRE DROp OF FlOW RaTES SENTRY GS MODElS GS20hh6lCZ aND GS20hT6aCZ (IN COMbINaTION WITh a TCO), aS WEll aS ThE SENTRY GT MODElS GT20DIa aND GT25DIa

pRESSuRE DROp OF FlOW RaTES SENTRY GT MODEl GT50II

Pres

sure

Dro

p [m

bar]

Flow Rate [m3/h] Air (d=1)1 2 3 4 5 10 15

1.0

0.7

0.5

0.3

0.2

0.1

1.25 2.50 3.75 5 6.25 12.5

GS20HT6ACZ

GS20HH6LCZ

GT20DIA GT25DIA

Flow Rate [m3/h] Gas (d=0.64)

Pres

sure

Dro

p [m

bar]

25 50 75

GT50II

1.0

0.7

0.5

0.3

0.2

0.110 40 60 8020

Flow Rate [m3/h] Air (d=1)

Flow Rate [m3/h] Gas (d=0.64)

R©

201

3 M

ertik

Max

itrol

Gm

bH &

Co.

KG

, All

Rig

hts

Res

erve

d.

Mertik Maxitrol Gmbh & Co. KGWarnstedter Str. 306502 Thale | GermanyTel.: (+49) 3947 400-0Fax: (+49) 3947 400-200 info@mertikmaxitrol.comwww.mertikmaxitrol.com

Mertik Maxitrol Gmbh & Co. KG The Valleys Innovation CentreAbercynon, South Wales CF45 4SN | UKTel.: (+44) 1443 665-720Fax: (+44) 1443 665-718Mobile: (+44) 7866-492 261info@mertikmaxitrol.comwww.mertikmaxitrol.com

Illustration TypeOrder Code

Connections Surface Dimensions[mm]

Weight[kg]

Cert. No.

Inlet Outlet L1 L2

GT10DIaGT15DIaGT20DIa

Rp 3/8Rp 1/2Rp 3/4

R 3/8R 1/2R 3/4

blue galvanized40.040.050.3

28.424.734.0

222732

0.050.070.10

DG-4

340A

Q123

6CE

-008

5BN0

394

GT25DIa rp 1 r 1 black galvanized 53.8 34.6 41 0.21

GT15DIIGT20DII

Rp 1/2Rp 3/4

Rp 1/2Rp 3/4 blue galvanized

45.554.5

---

2732

0.100.15

GT25DII rp 1 rp 1 black galvanized 61.5 - 41 0.30

GT32IaGT40IaGT50Ia

Rp 1 1/4Rp 1 1/2Rp 2

R 1 1/4R 1 1/2R 2

nickel plated

100.0112.0135.0

21.421.425.7

556580

0.951.422.60

DG-4

340A

Q126

0CE

-008

5BN0

395

GT32IIGT40IIGT50II

Rp 1 1/4Rp 1 1/2Rp 2

Rp 1 1/4Rp 1 1/2Rp 2

100.0112.0135.0

---

556580

0.951.422.60

GT32FFGT40FFGT50FFGT65FFGT80FFGT100FF*GT125FF*GT150FF*

DN 32DN 40DN 50DN 65DN 80DN 100DN 125DN 150

DN 32DN 40DN 50DN 65DN 80DN 100DN 125DN 150

nickel plated

138.0155.0175.0197.0229.0267.0224.0268.0

--------

--------

2.503.705.947.95

11.0015.3026.0032.00

GT15KD40GT20KD40GT25KD40

Rp 1/2Rp 3/4rp 1

Rp 1/2Rp 3/4rp 1

black galvanized75.590.0

121.0

---

273241

0.250.400.75

DG-4

341A

T005

2

GT32KD40GT40KD40GT50KD40

Rp 1 1/4Rp 1 1/2Rp 2

Rp 1 1/4Rp 1 1/2Rp 2

nickel plated185.0207.0246.0

---

556580

1.902.303.85

* despatch only by forwarder

Flange Connection

Internal Thread External Thread

L1

L1

L1

L1

L1L2

L1L2

all SENTRY GT MODElS / DIMENSIONS

For more information please refer to our literature “SENTRY GT/ SENTRY GT..KD40 thermally activated Shut-off Devices and

Ball Valves” (Literature code GTKD-LT-EN-09.2012) available at www.mertikmaxitrol.com.

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GS

H.G

T-LT

-EN

-10.

2013

-UK

Mertik Maxitrol Gmbh & Co. KGIndustriestr. 1 48308 Senden | GermanyTel.: (+49) 2597 9632-0Fax: (+49) 2597 9632-99 senden@mertikmaxitrol.comwww.mertikmaxitrol.com

EXCLUSIVE AGENTMaxitrol Company 23555 Telegraph Road|P.O. Box 2230Southfield, MI 48037-2230 | USATel.: (+1) 248 356-1400Fax: (+1) 248 356-0829info@maxitrol.comwww.maxitrol.com

Wrench Size

Internal Thread Internal Thread

Internal Thread External Thread

Internal Thread

Internal Thread Internal Thread