Hi

I am doing strss analysis on pig launcher for the first time. I do not know how to support the pipe connected to launcher. Shall I put an anchor/semi anchor on the support near the launcher nozzle? and do we consider any force applied on piping from launcher (I mean force applied on piping when launching the pig)?

Thanks

What is a semi-anchor ? Is that a bit like being semi-dead ? it's either an anchor or it is not. An anchor by definition restrains translations and rotations.

It is common practice to anchor piping ahead ofthe launcher and then design both launcher supports to slide axially.

This avoids the friction reaction from piping and usually very heavy, full bore valves reacting on the vessel saddle.

Some companies define semi/anchor as a support that restrains only translation, and anchor as a support that restrains both translations and rotations.

Thanks for the replies.

vanella is right semi anchor is only for translational movements.

Since the launcher here is not a permanent equipment in the system, I am not concerned about the thermal forces. My question is if we considering anything for the quickly applied force when launching the pig.

Thanks
Bobby

as i understand

we can consider launcher in sustained case analysis since it is using while pigging only. usually the allowable forces and moments at nozzles are given by vendors if not we can consider as pressure vessels and follow the ASME SEC VIII