Re: [PipingDesign] GRP Pipe Design

From: <M.>
Date: Thu Mar 13 2008 - 06:12:00 EDT

Dear Hafiz

The equations present at ASME B31.3 for pressure sizing of nonmetallic piping are limited. As result for pressure design, nonmetallic piping must comply with the listed standard in Table A326.1 or qualified per A304.7.2. ASME B31.3 have the following formula for RTR & RPM straight pipe

t= PD/2SF+P

Please request the vendor to provide you the design equation utilized in this regard. On what basis he specified the 18.1 mm thickness. Also request him to provide you performance test that include the effects of time, because failure of nonmetallic piping can be time-dependent.


> Hello,
> I want to ask about GRP ( Filament wound Glass
> reinforced plastic
> pipe )pipe design for the following conditions.
> Design Pressure = 6 Kg/cm2
> Dsign Temperature = 75 deg C
> We have send this data to vendor and vendor has
> proposed thickness of
> 18.1mm for 40" GRP pipe. Now i want to varify this
> thickness wether
> this is suitable or not. I have a formula from one
> of our previous
> projects for GRP pipe minimum wall thickness
> calculation . i.e
> Tm = 2.5 + (D/75)
> i dont have any code or standard for refrence of
> this formula. But
> when i use this formula for the calculattion of wall
> thickness for
> 48" pipe, it comes out to be 18.5mm. Thats why i
> want to check it
> again.
> Vendor has used AWWA C-950 and M45 for his
> calculation. but there is
> no Details for wall thickness in C950 and M45, they
> refer to ASTM
> D2992, 2996 etc etc. But there is no sufficient
> info.
> Although in ASME B31.3 there is a formula for the
> minimum pipe wall
> thickness, but i am unable to find Allowable Stress
> Values.
> So any 1 can suggest some solutions or can tell me
> Allowable stress
> values for GRP pipe.
> Regards
> Hafiz Ali Alvi
Received on Thu Mar 13 06:12:00 2008

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