BS78 design pressures 1

[Pete OB]

Hi,

I'm new to the forum but have a pipeline for potable water which has extensive use of BS78 and BS1211 class D pipe and fittings. The majority of the pipeline has been sliplined with PN16 HPPE pipe a while back and the system is now limited by the small section of original pipe that was not sliplined for various reasons.

I have tracked down copies of BS78 and BS1211 and they both have installation test pressures of 800 foot. The BS78 standard then goes on to say the suggested working pressure should not exceed half of the specified test pressure (i.e. 400ft) but then looking at the original system curves for the site this 400 foot pressure limit at the discharge of the pumps would have limited the flows from the pumping station to much lower than they were originally designed for so it seems that they must have designed the pipeline to have a higher working pressure than what is suggested in the BS78 code.

Does anyone have any further information that they might share to help guide what the original pipeline design pressure was when installed? I have searched through our drawings for ages and have been unsuccessful in finding any of the relevant design info from 1969 when the pipeline was installed.

Any and all help is gratefully received.

Cheers,

Pete OB

 

[LittleInch]

Only thing I can find seems to say 12 bar (1200 kPa).

So your 400 ft looks about right. Can't see Cast iron from 1969 being much higher than that.

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

 

[Pete OB]

Thanks for that. Really appreciate it.

Out of interest, where did you find something that suggested 12Bar? I'm always keen to read around things (i'm more above ground pipework and pumping minded myself).

I might need to look at options for sliplining the rest of the pipework too.

Thanks again for the help.

 

[LittleInch]

Google images.

It did say it was 1938 or something.

I'm sure there are a few you could pay for, but it does sound about right.

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