Guys,
The concern is not an inspector check. The standard states that the accuracy of the make-up method shall be proven. In fact, not only the method used but also the operational staff shall be qualified. As stated:
“Written procedures, incorporating the features of these provisions shall be...
BigInch,
For the ball valves commonly used in pipeline and manifold equipment, your proposal is valid. These valves are usually trunnion type, the seats seal against the ball, sealing the valve cavity in both closed and opened condition from upstream and downstream. Since the valve were not...
Mike,
I fear that, for this narrow tolerance range, even using a very precise control, all the bolts in the flange shall be simultaneously made-up and stretch controlled.
All this, in my opinion, is far from a reasonable practice for an equipment assembly shop.
If I am wrong, please, let me...
Guys,
API 17D (Design and Operation of Subsea Production Systems - Subsea Wellhead and Tree Equipment) has included in its second edition a requirement for flange make-up with bolts at 70% yield stress with an allowance of ±3% (see below).
“Closure bolting of all 6BX and 17SS flanges shall be...
Guys,
Is there anybody knows where to find material properties data to perform shakedown and ratcheting analysis for Inconel 625, 718 and 725 and Incoloy 825?
I thank you for helping,
HotStab.
Guys,
Is there any specific operational procedure that is suitable to avoid hydrate formation in valve cavities when changing from water injection to gas injection in subsea production equipment?
I would appreciate any guidance on this matter.
HotStab.
Costa,
It seems that you are concerned with missiles and not with a catastrophic vessel failure. In missile assessment the storage energy in the vessel is also an important input, but other constraints shall be also considered.
Take a look on the British report CRR 168, it is a very valuable...
Guys,
I really appreciate your comments. They did not change my basic concerns yet. However, it seems that this problem may have more than just one root cause and even the type of thread might not be a relevant factor at all. To be sure about it, a dimensional assessment of the threads shall be...
They are standard buttress threads 7°/45° per ANSI B1.9 with 3 TPI, class 2A/B.
Unfortunately, the threads did not receive appropriate coating (just phosphate) and neither hardness treatment.
In the first event with the heavier pieces, the galling occurred despite the use of grease (Alco EP 73 plus). After a tough battle, heating and loading, the pieces were unlocked and disassembled. The threads were refurbished and reassembled with a special procedure. A solid lubricant (Molycote...
Guys,
For the second time I have faced problems with large buttress threads. In the first event the thread was more than 25”ND and the parts to be connected were heavy (more than 10 kips). Nevertheless, the recent galling problem involved a bigger thread pair (28” ND) but lighter pieces (1200...
In UK you may contact Pacson <http://www.pacson.co.uk/> , Oliver <http://www.valves.co.uk/> or Bentley <http://www.lb-bentley.com/>. Gate valves of this size are also used in Christmas trees, so any manufacturer of subsea production equipment might be an alternative: GE Oil & Gas (Vetco Gray)...
Please, help me to understand the extension that a hydrostatic test shall be applied in equipment that has mechanical connections indirectly collaborating with pressure resistance.
As far as I know, the flange bolting submitted to hydrostatic pressure tests does not need be the same to be...
I would appreciate a help to clarify a basic issue.
I work for a multinational company, with many sites all around the world, manufacturing the same product portfolio. The engineering and manufacture documents are in a global system, which is accessible for anyone inside the company on-line...
