Tunstall Steam Trap Capsules® have been in service since 1985. Their warranty performance since that time has resulted in a practically nonexistent failure rate. The Tunstall Steam Trap Capsule® has changed the nature of the steam trap repair business.

Before the advent of stainless steel forming and TIG welding technology, steam traps consisted of thermostatic parts made by crimping and soldering of plated materials; this system resulted in products that had built in obsolescence. Hydro formed phosphor bronze bellows were more successful but the cost was considerably higher than common diaphragm cage assemblies.

Tunstall Steam Trap Capsules® are fabricated of TIG welded stainless steel which take advantage of existing Aerospace Technology, with extremely close manufacturing tolerances. Their stainless steel bellows counterparts can be found on commercial aircraft and aerospace equipment throughout the world.

Tunstall Steam Trap Capsules® retrofit almost all thermostatic steam traps made in this century. Each capsule is individually tested and calibrated before shipment. We believe Tunstall Steam Trap Capsules® are by far the best way to repair and upgrade existing traps for years of trouble free service.

We will be glad to manufacture steam trap interiors for any thermostatic trap assembly ever made. Our products provide the simplest, most effective installation and removal process in the business. We warranty all materials and take pride in being the best product available today.

  • 100% Stainless Steel Thermostatic Capsule, TIG Welded Construction

    Stainless Steel Spring (If Required)

    Stainless Steel Seat

    Stainless Steel Bellows

    EPDM Gasket Rated to 300°F (Saturated Steam)

    12 Month Warranty

  • Spring Type

    For low pressure steam radiator traps vacuum to 125 psig. Stainless steel bellows with corrosion resistant stainless steel plug and seat. All parts calibrated inside a heavy duty stainless steel capsule (housing) with a stainless steel spring inserted on a stainless steel post at the top of capsule (housing). The seat projection to be unthreaded to facilitate easy installation where the orifice in the trap body has no threads.

    Thread Type

    For low pressure steam radiator traps vacuum to 125 psig. Stainless steel bellows with corrosion resistant stainless steel plug and seat. All parts calibrated inside a heavy duty stainless steel capsule (housing). The seat projection to be threaded to facilitate easy installation where the orifice in the trap body is threaded. TC Tool to be provided for ease of installation.

    New steam trap covers may be necessary to facilitate the capsule installation and will be provided as required.