Fusible Plug Specification

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Unless otherwise agreed, the drawing and specification of standard Sinomas NPT fusible plugs are as follows:

 drawing of NPT fusible plugs from Sinomas

Thread sizes H(mm) T(mm) S(mm)
1/8"NPT 16 5 12
1/4"NPT 21 6.5 14
3/8"NPT 20 6 17
1/2"NPT 29 8 22

 

HS code:8481809000

Yield temperature: per specified

Tolerance of yield temperature: ±3K (normally within ±1.5K)

Material of plug body:  
Brass: EN12164 (CW614N), optional with Tin or Nickel plating
Stainless Steel: AISI316

Alloy: eutectic alloy with several components

Max service pressure: 3.5 MPa (high pressure version available)

 

Checklist

Please supply the following information when you order fusible plugs from us:

  1. plug body material
  2. yield temperature
  3. thread specification
  4. drawing (if different from the drawing below)
  5. other requirements
  6. order quantity

Material certificate and test report can be supplied upon request. Minor service fee may be charged depending on your requirement and order quantity.

Application note:

  • We make sure that all our products function as they are designed to be. However it is the customer's responsibility to choose the right fusible plug for their application.
  • Apply anaerobic sealing adhesive or thread sealing tape for installation to avoid leakage.
  • Please consult us if the service pressure of your application is higher than 3.5 Mpa.
  • Fusible plug does not protect against overpressure from improper charging practices. In other words, fusible plugs only operate on over temperature instead of over pressure.
  • We strongly recommend to replace the fusible plug after 12 - 18 months of service.
  • Occasionally replacement of fusible plugs from different manufacturers on existing equipment can cause leakage problem. This is due to the incompatibility of the sealing and threads even the difference is very small.