BS7159 Code for GRP piping system

[rkuhn]

Hi,

I've a copy of the British Code BS7159:1989 for design of GRP piping system. In point 7.3.4.2 it dictates for the longitudinal pressure stress the folowing equation:

Long. pressure stress = p (Di+t)/40t
where
p : internal design pressure
Di : internal diameter
t : design thickness

I' think that the 40 is wrong, and should be only 4.

Thanks

 

[rjstephens]

Hi rkuhn,

I would tend to agree with you, if you look in the technical referenc manual of Caesar II, longitudinal press stress is=p(di+td)/4td & circumferential pressure stress=mp(di+td)/2td

 

[DSB123]

rkuhn & rjstephens,
The equation you refer to is CORRECT. The 40 is right. Look at the units. The Pressure used in the formula is in bar and since the stress is to be in N/Sqmm the a factor of 10 comes in. (i.e. the pressure (in Bar) is divided by 10 to give N/Sqmm).

Hope this clarifies the situation!!!

DSB

 

[rkuhn]

thanks you both.

I've another question:

Can the BS:7159 be used with underground FRP pipe?

thanks