Combination valve consisting of quick-acting valve and control valve for a steam circuit and SIL 3 certified safety circuit
A combination valve for a steam circuit, includes a quick-closing valve and a regulating valve. The quick-closing valve and the regulating valve are arranged in a common housing. The regulating valve is displaceable by an active drive and the quick-closing valve is passively displaceable by the steam.
1. A combination valve for a steam circuit, comprising:
a quick-closing valve, and
a regulating valve,
wherein the quick-closing valve and the regulating valve are arranged in a common housing, the regulating valve is displaceable by an active drive and the quick-closing valve is passively displaceable over a full stroke between an open position and a closed position by steam of the steam circuit,
wherein the combination valve is configured to carry out a partial stroke test on the quick-closing valve when the regulating valve is in an open position during ongoing operation of the steam circuit, wherein the partial stroke test is characterized in that the quick-closing valve is only moved over a part of its full stroke.
2. The combination valve according to claim 1 , wherein the quick-closing valve can be exposed to the steam in such a way that it moves in a closing direction,
wherein the combination valve is adapted such that, on account of the movement of the quick-closing valve in the closing direction, a throttle point opens via which the steam can escape, so that the quick-closing valve is prevented from moving further in the closing direction and remains in a partial stroke position.
3. The combination valve according to claim 2 , wherein respectively one pressure transmitter is arranged upstream and downstream of the throttle point.
4. The combination valve according to claim 1 , wherein the regulating valve is embodied as a pressure-relieved tubular regulating valve.
5. The combination valve according to claim 1 , wherein the regulating valve is embodied as a pre-stroke regulating valve.
6. The combination valve according to claim 1 , wherein the quick-closing valve is configured with a sleeve-shaped quick-closing valve body and the regulating valve is configured with a tubular valve body,
wherein the tubular valve body of the regulating valve is guided on the inside of the sleeve-shaped quick-closing valve body.
7. The combination valve according to claim 1 , wherein the quick-closing valve and the regulating valve are able to travel independently of each other and the regulating valve in the closed state shuts off a flow of steam through the combination valve.
8. The combination valve according to claim 1 , comprising a switchable control valve for switching the quick-closing valve.
9. The combination valve according to claim 8 , wherein the control valve is a 3/2 way valve.
10. The combination valve according to claim 8 , wherein the control valve has a hydraulically or pneumatically embodied control drive.
11. The combination valve according to claim 1 , wherein the regulating valve has a regulating valve drive embodied as a low-pressure hydraulic drive or as an electric drive.
12. The combination valve according to claim 1 , wherein the housing is constructed from a housing base body and a housing cover, wherein the housing base body is connectable to the housing cover in a force-fitting and/or form-fitting manner.
13. The combination valve according to claim 1 , wherein the housing has a steam strainer at a steam entry port, comprising a steam deflection device by means of which the steam is deflectable by an angle of 10° to 80°.
14. The combination valve according to claim 13 , wherein the steam strainer is connected to a housing cover of the housing in a detachable manner.
15. The combination valve according to claim 1 , wherein the housing has a diffuser at a steam exhaust port.
16. The combination valve according to claim 15 , wherein the diffuser is arranged in a housing base body of the housing in a detachable manner.
17. The combination valve according to claim 15 , wherein the diffuser comprises a swirl-breaking device.
18. The combination valve according to claims 17 , wherein the swirl-breaking device is configured as a guide for the regulating valve.
19. The combination valve according to claim 1 , wherein, during operation of the combination valve, a back side of a quick-closing valve body of the quick-closing valve in an open position of the quick-closing valve is not under steam pressure.
20. The combination valve according to claim 1 , wherein the regulating valve has a stem shaft with a stem seal,
wherein the stem seal is exposed to ambient pressure on one side and is pressure less on an opposite side during operation of the combination valve.
21. A SIL 3 certified safety circuit comprising:
a combination valve for a steam circuit, the combination valve comprising a quick-closing valve and a regulating valve,
wherein the quick-closing valve and the regulating valve are arranged in a common housing, the regulating valve is displaceable by an active drive and the quick-closing valve is passively displaceable over a full stroke between an open position and a closed position by steam of the steam circuit,
wherein the combination valve is configured to carry out a partial stroke test on the quick-closing valve when the regulating valve is in an open position during ongoing operation of the steam circuit, wherein the partial stroke test is characterized in that the quick-closing valve is only moved over a part of its full stroke.