Union Type Holders

LaMOT Brand of Rupture Discs and Valves & Arrestors. Manufacturing quality products, using proven techniques, industry standards, and modern manufacturing methods since 1964.

Union Type Holders

Union Type Holders

The Union Type Holder is designed to provide flexibility of use in tight piping configurations. These precisely built holders combine remarkable ease of installation with high pressure ratings in pipe sizes of 2" (50 mm) or less. These holders are designed to be used with either Standard or Composite (LL) Rupture Discs.

When ordering rupture discs, please state whether the disc is to be installed in a Union Type Holder, and whether you require the standard configuration or a permanently attached 3-D flow tag.



Standard sizes, ratings and bores are shown in Table 12 & 13. Contact the factory for applications outside this range. Any combination of welded or threaded connections is available. All parts are available in Carbon Steel and 316 SS The units are designed with 30° angular seating. Identification of size, pressure rating and flow direction is laser marked  on the assembly. Refer to Table 4 and Table 5 for rupture disc details.

If the unit has a threaded outlet, it can be supplied with a muffled plug. This reduces reaction forces upon disc rupture, and redirects fragments or product from dispersing directly from the nozzle. For more information on the muffled plug, contact the factory.

The Wing Nut/Hammer Nut Union Holder is supplied with extra heavy hammer lugs. This design is a favorite of field personnel who must replace rupture discs in hard to reach locations.

LaMOT wing nut Union Holders are available in sizes 1”, 1½” and 2”. They have coarse threaded nuts and subs for maximum strength and easy assembly.

Hex Nut Union Holders are available in sizes ½”, 1”, 1½” and 2”.

Union Holders are supplied in standard materials of Carbon Steel and/or Stainless Steel. Other materials are available upon request. Refer to Table 12 & 13 for dimensions and holder ratings.


As a standard, rupture discs for use in Union Type Holders are shipped with a detached tag, which should be affixed to the completed assembly when the rupture disc is installed.
For those requiring positive identification of rupture disc installations, a special Union Type Holder allows the installation of a rupture disc with a permanently attached 3-dimensional flow direction tag. The 3-D flow tag extends beyond the holder for easier verification of orientation after the rupture disc has been installed (not available in 2” 2000# configuration).


ISO 9001 Certification

CE Certificates - The European Pressure Equipment Directive


ATEX Rupture Disc Device Certificate of Assessment

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