Tunstall spring type capsule TCBJ-1006 is used on Barnes & Jones 120V and 122V traps.
Tunstall steam trap capsules are welded stainless steel thermostatic elements precisely calibarated to ensure solid opening and closing. Capsules replace the existing thermostat & seat within your current trap. Capsules are held in place by a threaded protrusion at the bottom of the capsule that will thread into the orifice of your trap, or a high tension spring at the top of capsule that will have pressure applied by the cover to hold the capsule into the bottom orifice. When the thermostatic element senses steam it expands causing the ball type plunger on the bottom of the element to close against it's internal seat, thus keeping the steam contained until the steam cools to a liquid state. The element then senses the cooler liquid condensate and contracts which raises the plunger from the seat and allows the condensate to drain.