Hydrotest Blind Flange Innovation? 1

[mechanicalchad]

We are always reviewing of our piping fabrication and looking for ways to speed it up, and bolt-up for hydrotest always just naws at me. For how long hydrotests have been done, there MUST be a quicker way to bolt-up blind flanges, or maybe find a better way than blind flanges altogether.

Obviously hot bolting (half the bolts) is a non-starter, but does anyone else have any other innovative ideas out there for containing fluid in a piping system for hydrotesting? Maybe a quicker way to put on, and do up nuts? maybe tacking on stud bolts directly onto the blinds? ... something else?

I'd love to hear any ideas on this as this is an area where there's a ton of time that could be saved, adding huge value to projects.

Cheers,
Chad

 

[Gator]

Clamps! Or a Clamp-like Device.

Piping Design Central

 

[bimr]

Use an electric impact tool.

 

[pennpiper]

mechanicalchad,
You left out vital information.
A. Are you a manufacturing shop where you fabricate multiple objects and need to Hydrotest them prior to the next assembly operation?
B. Are you a Pipe Fab shop where you Hydrotest different configurations of pipe Spools prior to shipping?
C. Are you a Construction site where you are Hydro testing Piping systems in place?
d. Other (please define)?

Sometimes its possible to do all the right things and still get bad results

 

[pennpiper]

I forgot:
What are the Flange Sizes?
and
What are the Flange Ratings?

Sometimes its possible to do all the right things and still get bad results

 

[mechanicalchad]

Thanks for the responses! We do both field and shop, but I'm focussed on more the shop side of things now. Definitely multiple configurations. Nominal diameter ranges from 2" to 24" for the range we would look at, 150 Ansi to 2500 Ansi. The piping is both straight run piping, runs with tees, and drops out of pipe racks to buildings (spaghetti type). We use impacts as of now, but I was hoping to speed it up even more. I think the clamp type idea has potential.

 

[pennpiper]

If you decide to try the Clamp method I see some issues to think about. There are 13 flange sizes, 7 flange ratings, 2 metals (Carbon Steel and Stainless Steel) to consider. There is some size & rating areas where you may be able to double up but I think this is not much help. Then there is the question of how many Clamps you will need for each Flange joint. The 2” will need fewer clamps than the 24” but will the Clamp count be the same as the Stud Bolts count?

1. How many Clamps will you need?
2. What kind of Clamp will you use?
3. Will you design your own or is there something out there that you can use with out reinventing the wheel?
4. How will (are) these clamps qualified, tested, and certified?
5. How many times can one of these Clamps be used before it must be retested or replaced?
6. What will Clamps cost factored by the maximum allowable reuse?
7. What will Stud bolts cost factored by the maximum allowable reuse?



Sometimes its possible to do all the right things and still get bad results

 

[mechanicalchad]

You certainly raise some excellent questions. I think I would add the following:
8. Can we make a clamp be applicable to more than one i) size; or ii) ansi rating?
9. Are there other sealing methods to contain pressure at pipe openings?

Now I just wish these questions were easier to answer

I also wonder, would there be value in having the clamps certified if they were part of a destructive test each and every time? If, of course, we had a way of safely absorbing any possible failure that is. In my experience, run to failure is usually the most efficient in terms of component life (granted it may cause other issues in process conditions hence redundant and non-redundant designs there). However, if this was the case here, we could remove questions 4,5, and somewhat 6.

 

[StoneCold]

Mechanicalchad
Here is an idea for you, that might help you out in a way your not thinking of.
Video tape the hydotesting of a single lot of piping.
Watch the video and break the time down into operations. Setup, Bolting, filling, venting air, actual Hydotest, draining, unbolting, etc.
Then based on the time involved look for ways to shave time off the operations. Maybe bolt up is not what is using all your time or there are ways to shorten the total time that are easier than fixing the bolt up issue. Just a thought.

Regards
StoneCold

 

[mechanicalchad]

I like the video idea! The exact times for each operation would be ideal, but I just don't have that area tied into our cameras yet. It would also be interesting to see what types of things cause unnecessary delays: missing tools, etc.

I have a crazy, undeveloped idea rolling around in the back of my head that should cut down on most of those operations you mention though: setup, bolting, filling, venting air, draining and unbolting, but it only works if there's a quick way to seal off pipe openings which is probably why people don't do it.

 

[1gibson]

If you just tell everyone you are taping, I expect you will reduce the time by 20% or more.

I've been around a lot of hydrotest and what seemed to waste the most time was filling (with a garden hose...) and trying to find bolting (we got in trouble if we put bolting for hydro on our bill of material, and assembly didn't want to lose sight of the job bolting.)

Remember not to rush people too much. You lose all feel if you tighten everything with an impact gun. If (hypothetically) someone put 1.125-7 studs into 1.125-8 tapped holes with an impact socket driver, and then (hypothetically) tightened the nuts with an impact also, they might not notice, and (hypothetically) the blind flange could hit the ceiling once you were almost at full pressure.