Full Port in 1 Piece Ball Valve (Small Diameters) 2

[EngGab]

Hello Friends.

I have doubts about the manufacture of this type of valves with these characteristics, I will greatly appreciate the support they can give me.

It is required to install a branch of 3/4 "Ø for an instrument, this on a line in service (42" Ø), this will be done through a hot-tapping, therefore a ball valve is required, full port, 3/4 "Ø, SW x NPT end connections and at the customer's request, this valve must be 1 piece.

However until now I have not found a model that meets these characteristics 100%. My doubt of particular way for this type of valves in this diameter, if they are manufactured in full port of 1 piece. Since until now the models that I have found for full complete are of 2 or 3 pieces and for 1 piece only with reduced port, This basically for the maintenance of the internal ones.

Are full port valves manufactured in 1 piece?

In case of knowing about a manufacturer of this type of valve, I would appreciate your sharing the information.

If this topic is already published in another thread, I will appreciate the link. Thank´s.

 

[mk3223]

It seems you are correct that the google doesn't have the 1 piece full port of the ball valve.
Just wonder why requires 3/4" full port valve for the instrument connection, and why only 1 piece ball valve allowed.
Also, can the full port gate valve be used instead?

 

[bcd]

You can't find the valve because it is not possible to build a 1-piece ball valve with socket x NPT ends. You can get these in flanged end because the diameter of the raised face on the flange leaves enough room to insert the seats, ball, and stem and then hold it all in with an insert that forms part of the raised face. So 1-piece construction. Weld or thread end will require at least 1 body joint somewhere between the end so it is 2-piece construction. Customer specification cannot be met.

 

[EngGab]

mk3223 the ball valve is required because being a hot-taping it is necessary that the closure be as fast as possible, and the quarter-turn valves are the best option, as well as the full port (although the gate would also comply with this point), besides processes so indicates it. the request for 1 piece is from the customer, a point that has become clearer with the comment of "bcd" thanks, in fact I found some sites that corroborate this arguing bcd, attached as a sample provider plane (see item 71), apparently because the 1-piece design for these diameters requires a retainer to hold the ball and seats, which limits this design to a reduced port.

Now it would be excellent if someone knew of any specification or regulation to support this, I am still looking for it .. But if anyone could provide me with this information, I would appreciate it.

Thanks for helping me..

 

[moltenmetal]

There is no such thing as a truly "1 pc" ball valve. What they really mean by "1 pc" is "no body seal", i.e. the valve has only the stem seal as an external leakage point. Ball valves with single piece bodies in this sense (i.e. no body seals or flanges) are all "end entry", meaning that the ball and stem and seats are inserted from one of the ends of the valve. Doing the geometry on this, it is NOT possible to build a truly end-entry ball valve which is also 1 pc. You either end up with two different port sizes, or basically a huge "seat retainer" which has a body seal in it, i.e. your "1 pc" ball valve is indistinguishable from what is more properly known as a 2 pc ball valve.

You shouldn't weld either 1 pc or 2 pc ball valves, period. If you are welding a ball valve into a line, you should use a 3 pc valve so it can be disassembled prior to welding and the middle section swung out for maintenance. Otherwise, you are asking for seats and seals to be damaged during welding. There are some designs that are intended to be non-maintainable/throw away that try various things to make them possible to weld without disassembly. They're all kludged solutions in my opinion- they don't work very well in our experience. Stick with a 3-piecer, or use a gate valve. A top-entry ball valve would be another option, though I don't think it's such a good idea at 3/4".

 

[EngGab]

Thanks moltenmetal, certainly to be full port, the ball valves must be of 2 or 3 pieces. Thanks also for the recommendations to weld these valves since it is important to take care of the seats and the joints .. in this case we opted for valves with heat dissipating rings.

Thanks for all the comments. They have been helpful