Ratings for Socket Welded Fittings

Sachin,
Send me (via E-mail) the full Line Class Specification for this piping only.

Dear sir,

MR.SACHIN,

I think 6000# is coorect, as see the following dimensions.

3/4" - 6000# dimension 'D' bore is 0.642" /0.582" (16.307 /14.783mm).

3/4" - sch 160 pipe id is 15.596mm (0.614").

I am working in company manufacturing flanges and fittings. I donot know other factors of piping designing.

Thank you .

V.D.DEODHAR.

Hi Sachin,

There seem to be one or two anomalies in the specification data as you have presented it. The flange rating is given as Cl 150 RF which determines a certain pressure/temperature rating for the system. It is surprising then that the piping is required to be sch 160. I would have expected the piping to be sch 80 (max) for a Cl 150 system (or a higher flange rating for a sch 160 pipe). If the Cl 150 is correct, then 3000# socketweld fittings would be sufficient for the conditions. Of course, I am talking about a general system here, without knowing all the details of your particular case. I would suggest, though, that you review the requirements of the specification with your colleagues.

Could you clarify how you reach to this conclusion that S 80 is sufficient for Cl 150 ?

The two options available in spec are XS & Sch 160 . As per Spec , use Sch160 only when line comes from header /equipment upto first block valve as in our case.

As discussed , usage of S160 upto valve is due to sudden increase in pressure & to compensate higher pressure we have to provide higher wall thickness.Pl. let me know the logic behind.

Thks

It is according to what PSI and temperature of the system and also is the extra thickness for high wear? I doubt that you will ever have any where up to 3000 psi on the system. Also if you look up XS and Shd. 80 wall thickness you will find them to be identical up to 12" I believe and above 12" the Sch. 80 the wall will increase with OD size and XS will not increase with OD size. The 3000 lb, fittings are ok to use here IMO. From the information you give there is no particular pressure related need for Sch. 160 pipe here either. One reason that comes into mind about using the Sch.160 pipe on the first piece from the header is that it makes the branch much stronger in case the main header would hammer or move allot. Sch.160 was probably used there to help overcome stress factors not associated with internal pressure. I have many piping systems that run at similar pressures and temps. in the paper mill I work in and we use 3000 lb. socket weld fittings nearly always on these systems. It is also common to use heavier pipe on the first piece of branch pipe from a header. We have a very good pipe specification and we follow these specs. although we might decide to go over what the spec. would call out to use for reasons we learn from the experience of running the systems.