Dow Confidential

Chlor-Alkali Assets

Reliability

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Freeport Chlor-Alkali AssetsSlip Blind PolicyTraining Code 282539_1095

In order for the links to work, press F5 to view in slide-show view

Dow Confidential

Chlor-Alkali Assets

Reliability Background

The need for a policy was identified during the RCI process following the April 2013 HCL spill during the CARB plant outage (see Event 352891). 48” pancake buckled when ~20 psig of head pressure was

applied during chemical cleaning operation The leak resulted in approximately 20,000 gallons of weak

HCl solution being spilled to the slab and ditch.

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Chlor-Alkali Assets

Reliability Scope

The policy is intended to direct personnel working in Chlor-Alkali units in the proper method for selecting the correct slip blind and documenting slip blind usage.

EXEMPTIONS - • Blind flanges that meet the line or vessel piping specification and

spectacle blinds designed into the plant (i.e. electrolyzer spectacle blinds) are exempt from this policy.

• Blinds that are specified as part of a properly reviewed and approved plant operating or maintenance procedure that meets the evaluation and documentation requirements of this policy are exempt from the tracking log requirements.

• It is considered a good practice to include any temporary line blinds in the Slip Blind Tracking Log for a given job to ensure proper reconciliation at the end of the project or repair work.

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Reliability Root Causes

The RCI found the following were root causes of the incident and are intended to be resolved by standardizing blind practices across CAA: Hazard of bowed slip blind and column head pressure not

understood Slip blind not adequate for head pressure in column Inadequate awareness, training, and assessment of

existing policies No slip blind policy implemented in L&D

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Chlor-Alkali Assets

Reliability Important Information

All blind installation and removal activities in the CAA Reliability Zone are considered CRITICAL activities and are covered by one of the following procedures:

Com_CRIT_Slip Blind Installation and Removal Procedure.doc

Slip Blind Tracking Log for CAA

Production plants may have additional safe work procedures that cover specific pancakes installation activities.

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Reliability Roles & Responsibilities

The Freeport CAA Slip Blind Policy covers the responsibilities of the following roles:

• CAA Reliability Zone Leader• Production Plant Leaders• Approved Slip Blind Reviewer• Training Coordinator• Planners - Turn Around, WAC, Project, Field• Maintenance Do-Workers• Permit Issuer

Review the policy - know your responsibilities.

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Chlor-Alkali Assets

Reliability Requirement #1- Blind Labeling

All slip blinds will be labeled:

Material of construction Blind thickness (i.e. 1/8”, 1/4”, 0.125”) Nominal line size designed for (i.e. 3”) Flange class the diameter is designed for (i.e. 150#, 300#)

NOTE: this designation is strictly based on the flange class the blind dimensions are designed to fit and is NOT meant to indicate pressure rating

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Chlor-Alkali Assets

Reliability Requirement #2 – Blind sizing

Slip blinds will have a pressure rating which conforms to the piping specification of the system unless there is a documented basis for a lower pressure rating with supporting slip blind design documentation (one time calculation sheet or reference to blind matrices).

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Reliability Requirement #3 –Determination of Process Conditions

For all slip blind installation, the worst case scenario for temperature, pressure, and chemical content must be considered when determining the material of construction and thickness of the blind.

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Reliability Requirement #4 –Slip Blind Reviewer Requirements

All slip blind installations (daily maintenance, TA, or project) that do not meet the requirements of the pipe specification for the line in question will be reviewed and approved.

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Reliability Slip Blind Tracking Log

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1 123456789 4" pancake on brine line to T-201BOn 4" brine line right before it ties into top of T-201B. Vessel Entry 4" 150

Stainless Steel or Monel 1/8"

2 123456789 24" blind flange for T-201B Chlorine InletT-201B inlet nozzle after inlet spool is removed. Vessel Entry 24" 150

Carbon Steel or FRP Blind flange

3 1234567892" pancake on softwater line to D-203B Chlorine inlet.

Downstream of 2" manual valve on softwater line to D-203B chlorine inlet. Vessel Entry 2" 300

Stainless Steel or Monel 1/8"

4 1234567893" pancake on D-203B Chlorine inlet sniff line.

On D-203B side of 3" manual valve on sniff line on D-203B chlorine inlet. Vessel Entry 3" 300

Stainless Steel or Monel 1/8"

Reason for slip blind or blind flange

Slip Blind Specifications

Size, inches

Flange Class

Material on Construction

Slip blind thickness,

inches

Blind Tag

Number

Work Order or TA Job Number

Description Location

Continued

Example

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Chlor-Alkali Assets

Reliability Slip Blind Tracking Log (cont.)

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None - Manual valve and bypass valve upstream of AO-204F will be closed and bleed valve open, so no pressure will be on the line. 0 amb CA30 N/A B1-268-5051 Heath Tanner

None 0 amb CA30 N/A B1-268-5051 Heath Tanner

Softwater manual valve leaking by. 80 200 CA30 Softwater B1-270-5051 Heath Tanner

Sniff valve leaking by. 0.25 amb CA30 N/A B1-270-5051 Heath Tanner

P & ID No.

Approved DOA Blind Sizer Signature *only if

not per pipe spec, otherwise N/A

Blind installed and stamp verifed (permit

closer signature)

Blind removed after use (permit closer

signature)

Pressure Source and Notes on Max pressure requirements (i.e air gap, split gasket, double block and bleed needed)

Max Press,

psi

Max Temp,

F

Pipe Spec

Process Medium

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Chlor-Alkali Assets

Reliability Requirement #5 - Blind Installation/ Removal Tracking

All slip blinds will be tracked via the Slip Blind Tracking Log to document.

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Reliability Requirement #6 – Blind Identification

Blinds will be positively identified with a unique numbering system that matches the P&ID markup or annotated picture to avoid potential issues with installing blinds in the wrong location and to facilitate reconciliation of removed blinds. Green tags are one way to meet this requirement but other methods are acceptable such as project tie-point tags.

Prior to installation, workers will confirm that the size, material of construction, and flange class of the blind match the Slip Blind Tracking Log documentation for that specific location

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Reliability Requirement #7 – Work Authorization

No slip blinds or pancakes other than normal line blinds that meet the full requirements of the line pipe specification can be installed without the Slip Blind Tracking Log and marked up P&ID or annotated picture being attached to the job plan.

Operations personnel will not issue a permit for work without verifying this documentation is included.

Maintenance, project, and/or TA personnel will not install non-spec blinds without such documentation being provided. Blinds will only be installed if the label matches the tracking log and the job plan.

Blinds will only be installed at locations that have been positively identified per the block LEO policy (i.e. yellow tag attached).

Note: Many blind installation and removal activities will be considered Line & Equipment Opening work and will need to meet the requirements of that Life Critical Standard.

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Reliability Requirement #8 – Blind Inspection

Prior to installation, all blinds will be inspected to confirm good condition

Upon removal, all blinds will be inspected to confirm suitability for future use.

Any blind that has suffered corrosion damage or has been deformed by pressure exposure will be immediately reported to the person who approved the blind for use so proper near miss follow-up will occur.

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