Fusible plugs, occasionally also called fuse plugs, solder plugs, are thermally operated non-reclosing pressure relief devices which function by yielding or melting of the fusible alloys sintered in the plug body.
Fusible plugs only respond to over-temperature. Compared to other type of safety devices, they are simpler and require no maintenance. In the meantime they are very reliable if you buy from quality manufacturers like us.
SINOMAS has been in this market for 25+ years. We treat quality above anything else. This is not only what we say, but also what we do, in many aspects that you might not be aware of. We have the test facility in house, which makes every single product we deliver is qualified.
Custom Design & Manufacturing
We produce all the eutectic fusible alloys needed in house. Compared to other suppliers who source fusible alloys from outside, we know how and we know why. This is very important when you need to develop safety critical components.
All fusible plugs can be custom designed based on customer requirements. It can be either product development for new project, or replacement of existing fusible plugs from other manufacturers. The MOQ varies depending on the complexity of production.
Plug Material Options
Fusible plug body can be made with the following materials:
- Brass, with options of Tin or Nickel plating
- Stainless steel. The advantage is corrosion resistant and high mechanical strength
- Bronze, mainly used for steam boilers
- Aluminum. The advantage is lightweight. Alu body is required for fusible plugs for aircraft wheel tires.
Thread Type
Different thread types are popular in different areas and industrial segment. We are a global supplier and are familiar with the major thread specifications in the world: Metric, NPT, BSPP (G), BSPT (R), UNC, etc.
Due to the good machinability, brass is ideal for small batch (less than a couple hundred) custom manufacturing. However brass fusible plugs can’t withstand high process pressure. Be sure to check with us before ordering.
Fusible Alloy
Fusible alloys are low melting alloys (<230oC) that are mainly comprised of Bismuth, Tin, Indium and Lead. The compositions are different for different temperature ratings. RoHS compliant (Lead free) fusible plugs are available upon request.