Pneumatic test pressure of an LP Gas residential pipeline system operating at 15

Can someone let me know whether it is safe to pneumatically pressure test at 85 psig a LPGas pipeline system meant for supplying cooking gas to a number of flats in a residential complex? It is a multi cylinder (52 cylinders) installation connected to a cylinder manifold which receives gas at full cylinder pressure, say about 100 psig. The manifold is tested hydraulically at 220 psig. The first stage pressure regulator (PRS 1), which is fitted at the end of manifold reduces the pressure to 15 psig & the gas passes through 1" main pipeline at 15 psig. It reaches the customer's kitchen, through a series of branch lines, where a second pressure regulator (PRS 2) reduces the pressure to 0.5 psig. The pipeline feeds about 150 flats. My question is whether it is safe to test the pipeline between PRS 1 and PRS 2 at a pneumatic pressure of 85 psig, when its operating pressure is only 15 psig.

One such pipeline erected by me has been operating successfully for about 3 months & was earlier pneumatically tested at a pressure of 30 psig, as per Indian Standard 6044 Part 1, which requires testing to be done at 1.5 times the max operating pressure. Due to certain billing problems, the residential complex owner has terminated the contract of old gas supplying company. The new gas supply company says that it will supply gas only if the pipeline between PRS 1 & PRS 2 is tested at 85 psig. It says that its internal policy is to test residential colony installations at 85 psig & it does not follow IS: 6044 code. It also refuses to take any responsibility for any problems arising out of this high pressure testing. However, we are hesitant to do testing at such a high pneumatic pressure, as families are already living in the flats.

What are standard norms of pressure testing in common gas pipeline codes? Should we go ahead & do the testing at 85 psig? Will it be safe? Received on Wed May 31 22:44:00 2006