Need pipe end plate thicknesses, for hydrostatic test

[tonyb]

Required thickness of end plates welded in place for blanking off purposes in hydrostatic test, 2-1/2" and up to 14" diameter A53 GR.B Std.Wall Pipe with varying temperatures and pressures. I need calculations to achieve this, can anybody help?

 

[PVRV]

ASME Sect. VIII, Div. 1
UG-34

 

[grandnobi]

If you adapt this spreadsheet (applying ANSI B31.3 Par. 304.5.3) to your purposes, the results should be satisfactory.

http://203.108.4.103/~denniskb/work/blindth.gif

I once experienced a fillet weld failing during hydrotest, which held this type of provisional blank. Therefore I recommend not only to concentrate on the plate itself , but also to carefully design the weld. If feasible, I meanwhile prefer to replace provisional plates by buttwelded components, i.e. forged caps or blinded welding neck flanges (both as per pipe class specification).

 

[SooCS]

I dont recommend using welding a flat end for hydrotest. I have seen many small construction companies doing. Some, even made a pressure tap at the end of the flat piece for pressure gage. This is really inviting accident.

This is in violation of B31.3, ie non standard component.

Why not use a standard end cap instead. Sellect an cap end with the same schedule rating of your piping and you should be okay.

 

[DSB123]

SooCS,
Using a Flat End Plate is not in violation of B31.3. ASME B31.3 includes for this type of component (See Table 304.4.1).

tonyb,
You mention this end plate is for hydrotest purposes but mention different temperatures and pressures. I can accept differing pressures but why differing temperatures?? During hydrotesting temperatures are normally around the ambient. Basically it is important to consider the actual pressure and preferably use a full pen or partial pen weld as a minimum in lieu of a fillet weld. As PVRV says, ASME B31.3 guides you to use ASME Sect. VIII, Div. 1 UG-34.

 

[SooCS]

DSB123,

U r right for the first engineered piece. But for the subsequence hydrotest, most fab yards just weld any similar flat of metal they can find in the junk yard.