Road/Railway Clearance for Hydrotesting

[RiniEIT]

Does anyone know the distance you need to be away from a road or railroad right of way when hydrostatic testing untested pipe in the field?

Clause 8.7.1.4 of CSA Z662 states that the road or railway needs to be closed during pressure testing for pipe installed at a road/railway crossing. But at what distance from their R.O.W. can you still perform pressure testing in the field? Is there a rule of thumb for this?

Thanks in advance!

"The important thing is to never stop questioning" - Einstein

 

[BigInch]

I have not seen anything published about it.

 

[bimr]

It will depend somewhat on the application.

Generally, pipelines that are installed under railroads are encased per the requirements of each particular railroad. The casing extends as wide as the embankment at the utility crossing. The pipe encasement is to protect against track failure due to pipeline joint separation.

If the pipeline is cased, protection from hydrostatic testing failure is inherent in the design of the pipeline crossing.

If you are doing a pneumatic test of an uncased pipeline, that is a different scenario and an Exclusion Zone is warranted:

"A minimum distance of 100 feet shall be maintained between facilities that are being tested and the personnel conducting the test. The safe distance may be increased and the temperature probe, manifold and recorders may have to be set back further than 100 feet due to potential projectiles or extreme volume/pressure."

http://www.ingaa.org/File.aspx?id=18981

This recommendation is from the Interstate Natural Gas Association of America (INGAA).

The railroad should have an inspector on each project, but not sure if the inspector would be able to address the question further.

 

[LittleInch]

I don't have it available, but PRCI have published a document with crater size for different diameter pipeliins at different pressures in different spills which is a start point.

You won't find much issue over 10m from the pipeline.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[RiniEIT]

Thank you bimr. I guess one can interpret that excerpt to be the distance required from a road or railway R.O.W., where a person could possibly be standing next to it (although ideally it would never happen).

Thanks again.

"The important thing is to never stop questioning" - Einstein