Fusible plugs are used to keep the temperature of the fusible metal below its melting point. The fuse plugs operate as a safety valve when abnormal or dangerous temperatures build up in a closed vessel. They have low melting points, making them useful to be used in mechanisms that require high-temperature settings. Due to this characteristic, they are used on some boilers to provide added protection against low water level.

This fluid coupling overheating protection device is a needed component in your industrial set up. Constructed of bronze or brass, the pipe plug has a tapered hole, which is drilled through the length of the valve. It has an even tapered from end to end that is filled with a low melting alloy – mostly consisting of tin. Fusible plugs are of two types:

  • FIRE-ACTUATED: The boiler plug is an alloy of tin, copper & lead and has a melting point of 6° to 7°. One end of the plug is attached to the tire/hot gases while the other is in contact with water. In case the water level drops below the plug, tin melts and blows out. It will produce a whistling noise to warn the operator that it’s time to replace the plug.
  •  STEAM-ACTUATED: The plug is installed on the end of the pipe outside the drum. The other end of the plug is kept at the lowest permissible water level in the steam drum. The metal in the plug melts at a temperature below that of the steam in the boiler. The water around the plug is at a cooler temperature than that in the boiler as long as the pipe end is below water level. When the water level drops below the open end of the pipe, steam heats the fuse plug, which melts down the tin letting out a warning to the operator.

It is important to maintain the fusible plugs and replace them every year. Do not try to refill the old casings with new tin alloy as this would only harm the material and lead to a dangerous effect. It is advised to always use a new plug.

You have arrived at the right place to search for a new fusible plug. At JTC Valve Sales,  https://www.jtcvalvesales.com/blog we stock only high-quality valves and their accessories to maintain the specific standards demanded by the industries. You can get in touch with us at 440-346-1259 to discuss the specifications before you purchase.