Bolting Yoke

[WallytheWhale]

Dear Ladies, dear gentlemen,

I have a question regarding the bolting of the yoke of ASME/API valves.
Most of the time the bolting of the yoke of valves is the same as the bolting of the body-bonnet.
But this is not always the case. Now I’m checking drawings and the yoke bolting is not mentioned.

I’m trying to find in the ASME standard if these must be mentioned and if the material doesn’t have to be the same as the body-bonnet bolting.

For me it doesn’t make sense if the bolting s different as the service for the complete valves is the same, as well as the environment.

Can somebody help me on this?

Thanks
Wally

 

[The Obturator]

I don't know which valves in particular you are discussing, but there maybe dialog in one of the API specifications. ASME B16.34 (2017) 5.0 does indicates that materials for items such as bolting be able to meet the pressure and temperature conditions. I've attached the extract here.

*** Per ISO-4126, the generic term 'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[WallytheWhale]

Hi Obturator,

Thank you, that is a help!

The valves are mainly API600, API603, API623 (Gate, Globe).

But, is the bolting for the yoke not the same by the API standard?
In the drawings I'm checking, all materials are mentioned, except for the (eye)bolt and nuts pushing for the yoke (compressing the packing).

I know that it is mentioned somewhere in the in standard, but I can't find it.

Regards,
Wally

 

[The Obturator]

I just took a quick look at API-600 (2015) that I have.

Table 7 - Materials for Parts (other than trim)
"Bolting Gland & Yoke - Bolting Material at least equal to ASTM A307 Grade B"
Annex C of API-600 Identifies those parts

API-623 is similar and API-603 advises to a corrosion resistant grade.

You might want to confer with the vendor on the material selection and why it isn't shown on their drawings as it is in the API specs.

You mention an eyebolt. Presumably this is due to the weight of the valve. The material of this should also be referenced whatever it is, even if the part is not in API.

*** Per ISO-4126, the generic term 'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[Nick_Gray_88]

Hi Wally,
You say yoke, but also compressing the packing?
Are you talking about the part which compresses the packing or the part bolted to the bonnet for the gearbox or handwheel??