Fixed & sliding Saddle

In horizontal vessel , how to decide which saddle will be fixed one

Few things that I'd like to add:
1. The nozzles which are connected to other equipments will benefit if you place them closer to the fixed saddle so the movement will be minimized.

2. Place unconnected items such as Pressure Temperature gauges to the moving side so you don't have to bother about the effect of movement.

It is preferred to fix the end of horizontal vessel close to the pipe rack.

But in case of horizontal exchangers which is connected to U/G CWS & CWR headers,
exchanger is fixed at channel end (away from pipe rack) due to stress reasons.

IF you’ll look at the exchangers you’ll see the connections are at one end, this is the end you’d want to anchor. By anchoring here you’ll eliminate the stress to the piping connecting to the exchanger by directing the thermo growth of the exchanger to the sliding end.

Dear 11echo,
I have followed below criteria for deciding fixed and sliding saddle for the exchanger.

Case 1: If all the lines connected to exchanger are coming from pipe rack, It is fixed at bonnet end (rack side), to avoid expansion being transferred on pipe rack.

Case 2 : If the exchanger is connected to the under ground cooling water supply and return header, then it is fixed at channel end. Since the U/G and A/G interface is treated as anchor point so thermal growth of exchanger is not allowed at channel end.