I need help. The steam silencer that I am working right now is located on the top of piperack with an elbow immediately on the bottom with a hard support. I only add guide on the 4 support lug of the silencer and omit the bolts and let the silencer move up. Is this a common practice? or will I use spring instead.

EC Pagorogon,
The bottom bend just after the steam relief valve will experience the max. thrust force. So it is recommended to provide a rigid support at this point.All the vertical pipe length weight will be taken care by this support. A no. of guides can be provided in the vertical pipe depending upon the pipe length to provide the stability to the system.Spring support is normally avoided in such system because of vibrations, when pressure is released.I hope it will help.

Sneh Gupta
Stress Analyst
Fluor India, N.Delhi

Hi Pagorogon,

I assume the silencer size and weight are significant depending on the noise requirement. So, I suggest to use a sliding joint between SV release pipe after the elbow and silencer connection.
If the silencer has not been purchased you can ask supplier to design the joint in accordance with the displacement at the joint. Otherwise, you need to create one for your need.

It is common practice to support silencers on four lugs onto a structure provided. Bolts should take uplift and shear ( sometimes ) forces sourced by wind or quake and some thrust force due to pressure loss in the silencer . However, slots are needed for the thermal expansion of silencer.

A thermal compensator ( expansion joint ) might be used between silencer and release pipe. In case of lateral thermal movement I do not recommend to use an expansion joint. Simply, expansion joints in single or serial applications can not transfer shear force.

Ibrahim Demir
Design Engineer
Clyde Babcock Hitachi ( Australia )