{"product_id":"spirax-sarco-mst21-balanced-thermostatic-steam-trap","title":"Spirax Sarco MST21 Balanced Thermostatic Steam Trap","description":"\u003cdiv\u003e\u003cp\u003eThe Spirax Sarco MST21 Stainless Steel Balanced Pressure Thermostatic Steam Trap is a maintainable, stainless‑steel trap designed for tracing lines and small condensate discharge duties. It uses a balanced pressure bellows mechanism that automatically adjusts the discharge temperature as steam pressure changes and provides effective air venting during start‑up. The MST21 family is available in 1\/4 in, 3\/8 in and 1\/2 in connections (MST21) or 1\/2 in, 3\/4 in and 1 in (MST21H) with NPT or BSP threaded fittings, and has a design pressure of PN25 with a max working pressure of 21 barg. Internals are replaceable in‑line without removing the trap from the pipework, and three bellows options are offered: STD, SUB and NTS. Construction features include a stainless steel bellows, stainless steel spring, stainless steel baffle, a 0.8 mm stainless steel filter screen (316L) and a stainless steel gasket (304S15), all contributing to corrosion resistance. For tracing‑line installations, fit the unit vertically with the bellows horizontal and the inlet at the top and outlet at the bottom to ensure self‑draining; if horizontal installation is required, a drop leg before the trap is recommended. The MST21 is fully compliant with the European Pressure Equipment Directive 97\/23\/EC. Documentation includes TI‑P125‑08 and IM‑P125‑07, which cover operating range, dimensions, discharge capacity and installation guidance. \u003c\/p\u003e\u003c\/div\u003e","brand":"Spirax","offers":[{"title":"New","offer_id":46259657474282,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0716\/8039\/3450\/files\/GTG-STOCK-014.png?v=1788727428","url":"https:\/\/gtghardware.com\/products\/spirax-sarco-mst21-balanced-thermostatic-steam-trap","provider":"GTG Hardware","version":"1.0","type":"link"}