Motor-driven main Steam Trap Valve
Main steam trap valve STR is a cascade stage type high-pressure control valve, the valve is used on hydrophobic system of main steam and reheat steam pipelines in firepower power plant. Control of high temperature and high pressure and dropping water saturation, high temperature steam trap is electric or pneumatic, also can be in manual operation. Pneumatic or electric trap type is STR, manual trap type is MTR, which is one of key valves for the large-scale firegenerating set.
Main advantages of high temperature steam trap valve
When fluid passage is cascade stage, continuously changing the direction of fluid, the speed should be controled to 30m/s to prevent cavitation damage.
Sealing surfaces and throttling surface separate,different throttling components are installed according to hydrophobic flow rate, the main valve components have been hardness treatment, hardening degree can reach about HRC70, closed tightly, a long service life.
Body assemblies using internal pressure seal structure, the bigger the pressure difference is, the better the sealing is .
Body assemblies and actuator adopts floating connections. Which can eliminate blocking rigidly phenomenon by core and push-rod not being one heart.
Technical parameter and performance
Body type cast or forge straight-through type body
Nominal diameter DN65，80，100，125，150，200，250，300
Nominal pressure PN1.6,4.0,.6.4Mpa
Connecting type flangr-connection BW weld
Material WCB
Working temperature is less than 420 degree
Packing high-temperature graphite knitting packing
Internal Components
Core type pressure-balanced type simple-seat valve core
Flow rate features equally percentage or linear
material 440B particular king of stainless steel
Executive Mechanism
cylinder piston or motor-driven executive mechanism
air-supply pressure: 0.5Mpa
air-supply connector :RC1/4
environment temperature :-30-70 degree
Enclosure（pneumatic executive mechanism）locator， hand wheel mechanism， air-filter reducing valve
Performance
Leakage quantity metal seat abide by standard comform to ANSI B16.104—1976 IV level
Return difference less than 3% of the overall route(no locator) less than 1% of the overall route (with locator)
Linear less than+-5% of the overall route(no locator) less than +-1% of overall route(with locator)
Adjustable range 50：1
Body
Nominal diameter DN25,32,40,50
Nominal pressure PN32, 42Mpa
Connecting medel BW weld-type
Material 12Cr1MoV forge piece
Temperature of the medium less than 560 degree
Internal Components
valve core model maze telescope-feed internal components, cascade stage telescope-feed internal components
Material stainless steel
Packing knitting packing of asbestos and graphite
Fluid direction high-in low-out
Executive mechanism cylinder, motor-driven, and manual executive mechanism
Action model two actions:gas-open and gas-close types
Leakage quantity comform to ANSI B16.104—1976 V level
Return difference less than 3% of the overall route（no locator）
Linear less than+-5% of the overall route（with locator）
Standard of enclosure executive mechanism hand-wheel mechanism two-position-three-way magnetic valve
Nominal Diameter and Rated Route
| nominal diameter DN | 65 | 80 | 100 | 125 | 150 | 200 | 250 |
| rated route mm | 40 | 40 | 50 | 50 | 60 | 75 | 75 |
