Method of Statement for Pneumatic Testing of Distribution and Process Piping System

The scope of this method of statement is to define the methodology for pneumatic pressure testing of any kind of distribution or process piping system.

During the activity and works, there will be continuous communication arrangement among all parties i.e. Project Management Team, hydro/pneumatic pressure testing engineer and all personnel working on site.

Below is list of equipment and instruments necessary for doing the pneumatic testing.

Air Cylinder

6” Manifold with ½” & ¾” connections

Pressure / Temperature recorder

Set of hand tools

Pressure Relief Valve

Set of other valves & fittings as per test specification

20 m ½ ’’ air hose

Set of pressure gauges

General Site Safety Requirements for Pipe Pneumatic Pressure Testing

• The work site’s safety representative will induct all
• Project Engineer will ensure all requirements of the permit are met before commencing works.
• Barriers and Warning signs will be erected to cordon off the area of testing or other hazard and only authorized personnel allowed within the
• All hoses, temporary fittings and instrument will be tested to 1.25 times of test pressure.
• Ensure valve status
• Should any leaks occur, pressurization will be stopped, and the leak is to be If the leak cannot be isolated, the system will be depressurized to atmospheric pressure before rectification work may be allowed.
• Valve under pressure should be opened and closed
• All hoses should be secured at regular intervals to prevent flailing in the event of failure.
• On completion of Pneumatic testing operations, all barriers should be removed.

Project Specific Safety Requirements

The following safety requirement will be reviewed and implemented prior to the commencement of each phase of operational activities related to pipe pneumatic pressure testing.

Prior to commencement of operations all personnel will attend a site safety meeting, and during operations they will adhere to site safety rules.

All requirements are defined in the Contractor Project Construction HSE Manual shall be complied with in carrying out the works.

Prior to start operation the hydrotest engineer will ensure that all work permit requirements have been completed and the site supervisors are aware of safety hazards.

Prior to commencement of operation the test supervisor will ensure those safety equipment requirements have been identified and adequately provided.

Prior to commencement of each new activity, or at each oncoming shift charge, a tool box safety talk shall be carried out by the site supervisor.

Prior to commencement of new shift a hand over form shall be filled out by supervisor.

All the personnel involved in the pressure testing and rigging operations shall be briefed about all the possible risks involved with the operation during the tool box meetings.

As the piping systems are pressurized the area of the pressure testing shall be barricade suitably restricting the entry of personnel not involved in the testing operations.

At the boundaries Notice / Sign boards shall be displayed with caution notes like “System Under Pressure do not enter” / Pressure Test in Progress” etc.

Valid test certificates by third party inspection provider on all safety devices shall be available.

On completion of activity, remove all the barriers and signs etc.

Equipment Pre-Mobilization Checks & Function Testing

The following describes the checks & function tests that will be carried out prior to mobilization to site.

Collate all Equipment’s/ Instruments certification and cross reference serial numbers against instruments.

Pressure test hoses to their rated working pressure for a minimum of one hour prior to mobilization from yard

Check instruments are indicating correct pressure compared to other instruments.

Hoses shall be rated for a minimum of 1.25 times the hydrostatic pressure anticipated for the operations.

Check all the consumable are of the correct quantity and quality.

Ensure all equipment lubricants are topped up and uncontaminated.

Check setting of equipment pressure relief valve are set at appropriate pressure

All test instruments shall be calibrated and certified by third party inspection with six months validity to be shown before filling and testing operations.

Pipe Line Pneumatic Testing Preparations

All permanent in –line instrument probes shall be removed and /or otherwise isolated

Equipment’s will be set up at work site.

Temporary barriers and warning tape will be erected around the work site.

Air Cylinder / Air Compressor is properly connected to the Manifold

Proper connections to be made to the manifold, Globe Valve to be connected to the inlet and outlet of the manifold

Pressure relief device shall be provided, having a set pressure not higher than the test pressure plus the lesser of 345 kPa (50psi) or 10% of the test pressure.

Pressure gauges shall be fitted

Make sure that all flanged joints and threaded joints are properly tightened.

Obtain approval from Site Manager/Safety advisor/Clint Representative for pneumatic pipe testing.

Before start of operation a safety meeting shall be held to discuss on topic of operating pressure hazards and precautions to safe working, highlighting as minimum the following topics:

• General Safety
• Review Job Safety Analysis JSA’s
• Operation Pressure
• Equipment Layout
• Duration of operations

Initial Pressurization and Leak Testing

Filling and Pressurization:

Pressure shall be gradually increased until a gauge pressure which is the lesser of one half the test pressure or 170kPa (25psi) is attained.

Which time a preliminary check shall be made, including examination of joints in accordance with para 341.4.1 (a) of ANSI B 31.3. Thereafter, the pressure shall be gradually increased in steps until the test pressure is reached, holding the pressure at each step long enough to equalize piping strains.

The pressure shall then be reduced to design pressure.

A leak test shall be maintained for at least 10 min, and all joints and connections shall be examined for leaks.

A manual pressure relief valve shall be installed on the manifold and test pressure shall be monitored accordingly by testing engineer / supervisor.

On reaching the test pressure, the connection of the air compressor / air cylinder shall be isolated from the piping system.

For pressure readings two calibrated pressure gauges shall be installed.

Inspection for Leaks

Soap solution shall be applied to all threaded and/or welded joints under air pressure test.

Access to all joints under test shall be provided.

If any leaks are found, the line shall be depressurized completely from the location of the leak by suitably closing the valves.

Necessary repair/replacement shall be carried out. All NDE to the original line class requirement are completed and approval from contractor shall be obtained before the system is retested.

If the leaks are from flange / gaskets / bolting, the pressure shall be reduced to 10-20% of test pressure, before retightening of the bolts.

Test Records

After witnessing the pressure test, all parties shall sign the Original Piping Pressure Test Report.

Depressurization

After successful completion of test, the line shall be depressurized by gradually opening vent valve/ depressurizing valve.

Ensure that nearby erected items are not affected by heavy blow of air during depressurizing the system.

Reinstatement

All the items which are removed for pneumatic test, shall be reinstated and the Pipe “Post test Critical Component Reinstatement” shall be signed off by all the concerned.

The signed format shall be passed on to the Contractors QA/QC Manager.

After the reinstatement, all instruments shall be visually checked & recorded.