Task 32+33 Purging a pipeline in/out of service

Large pipe segments to be purged are often accompanied by step by step instructions referred to as _____________________

a purge plan, written procedure

People not involved in the purge operation should be located

a safe distance away

Small diameter pipeline is most commonly purged out of service using ___________

air

If a main with service lines is to be purged into service, it is important to verify _________________________ are closed

all riser valves

Who should be notified before beginning a purge operation- select all that apply a. OSHA b. Gas dispatch c. emergency officials (fire department) d. town/city government official

b. Gas dispatch c. emergency officials (fire department)

When cutting out a section of metal pipe, before making the cut the pipe should be _______________ between the sections to remain

bonded

________________________ between induction point and discharge point should be maintained at all times during purge operation

communication

To prevent accidental ignition the purge stack needs to be

grounded

Static electricity is more prevalent when humidity is ________________

low

The vent stack should be constructed of _________________

metal

If when purging into service the readings are 95% gas but no odor is detected what is the reaction

notify appropriate personnel

The reason nitrogen is sometimes used is to

prevent an explosive gas to air mix

To purge a pipeline in to service you are replacing _________with ___________

replacing air/inert gas with natural gas

The purge stack should extend at least ________________ above ground

six feet

When purging a large diameter pipeline in or out of service _____________ of inert gas is used to prevent a dangerous mis of gas and air

slug

The diameter of the purge stack should be _____________ than the diameter of the pipe being purged

smaller

Cell phones, engines, electric lights, some flashlights, some two way radios are __________________________________ which need to be kept out of the purge area

sources of ignition

When doing a purge these should be eliminated as much as possible

sources of ignition

The most likely pace for an accidental ignition to occur would be at_____

the vent stack - point of discharge