The document provides information on the breech-lock arrangement used for shell and tube heat exchangers. Some key points: 1. The breech-lock arrangement was invented in 1960 by Standard Oil Co. of California and the first unit was put into operation in 1966. 2. Over 1400 breech-lock exchangers are currently in service, particularly for high temperature and high pressure applications. 3. The breech-lock arrangement allows for reliable sealing at high pressures, in-service re-tightening of tube sheets, and easy maintenance through its simple bolt design.

1. Info on Breech-Lock Arrangement on Shell and Tube Heat Exchangers:
1
2
3 Compared:
4
5
6
7
8
1960 : Invented and developed by Standard Oil Co. of California . The first Breech-Lock was
put into operation in 1966. Chevron was the Licencee to issue Licence to Fabricators.
1982 : ABB Lummus Heat Transfer, became a licensee for the worldwide marketing of high
pressure Breech-Lock heat exchangers. Over 1400 Breech-Lock exchangers are in service
Used in High Temperature/High Pressure Units with rich hydrogen streams in Hydrocrackers
/ Hydro-treaters, Gas Compression, Ammonia /urea Synthesis, Methanol Plants
Reliable High Pressure Performance Sealing. In Service Seating of Internal Gaskets. Spiral
Wound Gaskets are Used in the Girth Joints. Re-Tightening of Tubesheet Gasket, During
Operation Possible. Tightening of Gasket by Relatively Small Size Bolts. Easy and Quick
Maintenance. Eliminates the large channel cover flange and heavy bolting
Channel Cover is Relatively Thin and Light. Hydrostatic Load Of Channel Cover Is Absorbed
by the Channel Forging. Avoidance of High Stressed Zones in Pressure Parts
Ready made jigs-fixture assembly available for Easy Dismantling/Reassembly & for
Inspection. No Threaded Holes in Forging or in the Cladding.
2007 : After some leak problems and accidents, improvements were made to the screw
plug type and Advanced Breech-Lock Arrangement is now available.
JGC Annamalai
Advanced Breech-Lock Arrangement
Breech-Lock (Screw Disc) - Channel Internals - Assembly
Tube
(for Shell & Tube Heat Exchangers)
Thread Lock Ring (TLR)
Inner Compression Ring
Outer Compression Ring
Channel Barrel
Split Ring
Tube Sheet
Diaphragm Disc (Gasket Retainer)
Channel Box(Partitioned)
Internal Sleeve
Channel Cover
Internal
Flange
Gasket
Set Bolts
Locker
Ring
(Typical Illustration for channel assembly & for leak study. Detailed Design may Vary)