Seismic Restraint for Equipment and Building Services
An earthquake moves the building, and everything fixed to it tries to stay where it was. Equipment slides or tips, pipework and ductwork swing, and what falls can injure people or shut a building down. Restraint ties these services back to the structure. Which kind depends on whether the equipment is isolated, stands on the floor or hangs from the slab above.
The range
Isolators, snubbers and bracing
Seismic Isolators
Isolation and seismic restraint in one mount, for floor-mounted equipment on springs or rubber.
Restrained in every direction · movement limited to 6 mm (1/4″)
See the products
Seismic Snubbers
Rubber-lined stops beside open spring isolators or pads, or alone where the equipment is not isolated.
All-directional or lateral · 6 mm (1/4″) gap
See the products
Seismic Bracing
Wire-rope bracing for suspended pipework, ductwork, cable trays and equipment.
Ready-to-use kits or bulk components · tested to ANSI/ASHRAE Standard 171
See the products
Restraint beyond the standard range
Large-capacity snubbers for chillers, cooling towers, generators and tunnel fans, and seismic isolator housings for loads above 6,220 kg per mount, galvanised where the site calls for it. Sized to the equipment, drawn and supplied by us.
Snubbers and seismic isolators · sized to each equipment
Ask us for a selectionChoosing a restraint
Floor, isolator or slab above
The first question is how the equipment is held up; the second is whether it is isolated. The selection and its anchorage are a calculation we do for you.
| Criterion | Seismic Isolators | Seismic Snubbers | Seismic Bracing |
|---|---|---|---|
| Holds | Floor-mounted equipment that must be isolated | Equipment on open springs or pads, or bolted down | Suspended pipework, ductwork, cable trays and equipment |
| Isolation | Built in, spring or rubber | From the isolator beside it | Works with isolated and rigidly hung services |
| How it holds | A housing around the spring or rubber | A rubber-lined stop on the structure | Wire rope in tension, braced in pairs |
| Movement before it engages | 6 mm (1/4″) | 6 mm (1/4″) | 6 mm (1/4″) of rope slack |
| Typical use | Chillers, pumps, AHUs and generators on rooftops and in plant rooms | Equipment already on springs or pads, inertia bases | Sprinkler mains, ductwork, cable trays, suspended fans and units |
Isolated equipment
Restraint that leaves isolation working
A restraint that touches the equipment in normal running short-circuits the isolator and carries the vibration straight into the structure. Ours leave a 6 mm (1/4″) gap, meet the equipment on rubber, and never let metal touch metal.
Related productsVibration Isolation Spring and rubber mounts, hangers and inertia bases that stop equipment vibration reaching the structure.
Buy online
Our standard seismic isolators are sold through Fixing Smith, our online store. Snubbers and bracing come directly from us.
Related engineering services
Send us the equipment and where it stands.
We will select the restraint and tell you what the anchorage calculation needs.