Q & A > Question Details
In Hydroprocessing units, in case of a Leak in the Breech Lock Exchangers, can maintenance be done without reducing System Pressure and without stopping Feed to the Unit?
04/03/2020 A: keith bowers, B and B Consulting, kebowers47@gmail.com
These heat exchangers operate at high pressures and temperatures. Stopping a leak at the end gasket(s) by tightening the 'push bolts' may be possible. However, often these bolts will not turn easily when under system pressure and threads will gall and fail. Previous maintenance experience (disassembly) may provide some guidance on whether or not tightening the 'push bolts' is possible.

Injection of a 'sealant' into the leaking gasket joint may be workable if the leaking area is accessible. This type of closure has gaskets 'trapped' such that the risk of blow-out to the outside is highly unlikely. However, engineering analysis of the injection pressure should be performed to avoid exceeding the yield pressure of the push bolts.

Of course, a tube leak inside the shell cannot be repaired 'on-line' under system pressure, and requires disassembly and installing tube plugs.
24/02/2020 A: S Sivasankaran SABANAYAGAM, CPCL, cpclsiva@yahoo.com
Possibility of attending leak in breechlock exchanger considering different scenario (since it was not indicted in your query) is as follows
1. Tube leak - Maintenance can be done only after isolating the equipment and opening TLR.
2. Intermixing of Shell to tube side or vice versa due to leak at shell to tube sheet gasket joint - can be attempted onstream by tightening inner push bolts of TLR.
3. Leak from tell tale hole drilled in channel barrel : can be attempted onstream by tightening outer push bolts.
For Sl no 2 and 3, procedure provided by exchanger manufacturer needs to be followed.
Sr. No : 2 Possibility of arresting the leak is less than 50 % and it depends upon how quickly leak was identified
08/01/2020 A: Jon Isley, Fluor, jon.isley@fluor.com