API Flange 1

[Erkamal]

Hi frds,
i am seeing body bonnet non standard material table of API 6A 20th th edition. Table no 5.

they mention 60k & 70K material for inegral flange but in valve body with inegral end connetion ( flange ), they mention 36k, 45k, 60 , 75 k,
so if forge or cast valve body with integral eng connection , shoduld i follow 60 k or 75 k material or i can use 36K or 45 k material ?

if 36 k & 45 k material as a forged or cast body , is there any change in integral flange length or other flange dimensions?

 

[SPDL310]

You should follow the 60/75K yield condition for the integral flange. The 36K and 45K requirements are for valve bodies and bonnets that don't have an integral flange. You can have a 36k or 45K yield valve body or bonnet if it doesn't have an integral API flange. In order to be a monogramable item the integral flange needs to comply to the published dimensions.

 

[Erkamal]

Thx lot for your reply.

Little confusion for blow points :

1. in API 6A , one of clause , they mention that end connection shall be internal part of the body . if body is forged or cast and can take 36k/45k/64k/75 k material.but integral flange with 60k/70k material only. so should i take only 60k/75k material fogred bar for body ?

2. if body end conection by weld only then body and end connection can take 45k material also. so i do not understood that whcih thing play role for using higher strength material.
3.do not clear becuse..weld is a one type of joint and skill base work and forge is single piece. But then also forged body require higer strength than weld body.

 

[SPDL310]

1.) The standard can be confusing at times, but I believe the rationale for the increased yield requirements for the flanges is that API has designed the listed flanges. Therefore they control the design requirements for those flanges, and they are giving the design requirements for their flange to be manufactured from at least 60K material. API publishes no dimensions for valve bodies in 6A and leaves the design requirements for those to be determined by the manufacturer. If you are making a valve body with an integral flange yes the flange requirements will supersede the standard criteria for the valve body.

2.) An API welding neck flange will have the same yield requirement as the integral flange so in the best case you would be welding a 45K body to a 60K flange if you have a qualified welding procedure to do so. If you are making a weld in valve the design requirements are determined by the piping spec.

3.) Look at the last row under the end connection heading, and the referenced note c. That means if you are designing your own end connection the yield requirement can be as low as you want provided it meets the design requirements of part 4. If you are using another type of connection IE an ASME B16.5 flange the yield requirement for the integral body and flange would be the higher of the listed requirements for bodies in the respective pressure range or the ASME requirements.