Safety during Hydrotest

Everything related to Health, Safety & Environmental issues of any Petrochemical industry or Oil & gas sector.
IrfanAli
Posts: 3
Joined: 16 Jul 2010, 09:27
Area of interest: Mechanical Engineering

Re: Safety during Hydrotest

Post by IrfanAli »

The formula given provides some interesting results:

Assuming pressure to be 285 bar in a pipe of 20 m length and 4" internal diameter, the safe distance comes out to be 3.71 m. It does not appear rational.
arcpro
Posts: 299
Joined: 16 Apr 2010, 18:46
Area of interest: Manufacturing Engineering

Re: Safety during Hydrotest

Post by arcpro »

I believe that 3.71 m on each side of the whole piping circuit for safety purpose is enough for 4" dia line.
As a general rule, not following the formula, for any hydrostatic test, the safe distance our Safety guys recommends for barricade is 15-20 feet.
Qaiser
Core Member
Posts: 43
Joined: 29 Mar 2010, 06:46
Area of interest: Chemical Engineering

Re: Safety during Hydrotest

Post by Qaiser »

I second arcpro.
3.71 m = 12 ft approx.
It seems logical for water being incompressible fluid which depressurizes quickly.
I've searched a lot in response of IrfanAli's last post.
The fromula is from some Norweigan Specification (no soft copy or even Spec. No. avaiable yet or even any other similar document addressing this question)
Some useful tips (not rules) found:
- Don't stand in front of plugs.
- If hydrotesting above 6,000 psi, put the vessel in a pit cleared of personnel.

Queries are welcome.
Qaiser
mechcolor
Posts: 216
Joined: 17 May 2010, 18:05
Area of interest: Manufacturing Engineering

Re: Safety during Hydrotest

Post by mechcolor »

I also didn't find any reference of the said formula but to me 12 ft barricade distance for 4" pipe is reasonable.

Qaiser,
What do you say in case of piping?
Qaiser
Core Member
Posts: 43
Joined: 29 Mar 2010, 06:46
Area of interest: Chemical Engineering

Re: Safety during Hydrotest

Post by Qaiser »

The above formula seems logical for piping.

But if you are asking that what if a piping, instead of a vessel, is being hydrotested above 6,000 psi? as piping can't be put in a pit always.
I couldn't find any other reference / standard to address this issue.
But again I'd recommend to use the above formula for water being incompressible fluid.
I've come across a practical example of hydrotesting a 12" dia piping @ 287 bar with 15 ft barication around.

But if you are afraid of using the above formula, you may clear the area around as far as you can (preferably the whole site, you may do it in lunch break, etc.) & may put your inspection personnel behind a wall of specific strength or in a bunker. This is what we do for pneumatic testing on high pressures.
arcpro
Posts: 299
Joined: 16 Apr 2010, 18:46
Area of interest: Manufacturing Engineering

Re: Safety during Hydrotest

Post by arcpro »

Thanks Qaisar for the elaborated reply.
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