CN-122014886-A - Pressure reducing valve for high temperature fluid

Abstract

Pressure relief valves are described herein. An example pressure relief valve includes a valve body defining a fluid passageway between an inlet and an outlet. The valve body includes a first body portion having a first side with a first opening and a second side with a second opening. The second opening forms an outlet of the fluid passage. The first body portion is constructed of a first material. The valve body also includes a second body portion coupled to the first side of the first portion. The second body portion has a passageway aligned with the first opening. The second body portion forms an inlet for the fluid passageway. The second body portion is constructed of a second material having a higher temperature level than the first material. The pressure relief valve further includes a nozzle and a movable flow control member.

Inventors

• ZHU XINWEI
• Shi Qiduan

Assignees

• 艾默生自动化流体控制(上海)有限公司

Dates

Publication Date

20260512

Application Date

20241031

Claims (20)

1. 1. A pressure relief valve, comprising: a valve body defining a fluid passageway between an inlet and an outlet, the valve body comprising: A first body portion having a first side with a first opening and a second side with a second opening, the second opening forming the outlet of the fluid passageway, the first body portion being composed of a first material, and A second body portion coupled to the first side of the first body portion, the second body portion having a channel aligned with the first opening, the second body portion forming the inlet of the fluid passageway, the second body portion being composed of a second material having a higher temperature grade than the first material; A nozzle disposed in the fluid passage, the nozzle having an end forming a valve seat, and A flow control member movable relative to the valve seat between a closed position and an open position.
2. 2. The pressure relief valve of claim 1, wherein the first material of the first body portion is C12A and the second material of the second body portion is G115.
3. 3. The pressure relief valve of claim 2, wherein the first end of the second body portion is welded to the first side of the first body portion.
4. 4. The pressure relief valve of claim 3, wherein a weld material is deposited between the second body portion and the first body portion.
5. 5. The pressure relief valve of claim 4, wherein the weld material is E9015-B91.
6. 6. The pressure relief valve of claim 3, wherein the first end of the second body portion is welded to the first side of the first body portion by butt welding.
7. 7. The pressure relief valve of claim 6, wherein the first side of the first body portion and the first end of the second body portion are angled away from each other in a radially outward direction.
8. 8. The pressure relief valve of claim 1, wherein the second body portion has a first end, a second end opposite the first end, and a channel between the first end and the second end, and wherein the first end is coupled to the first side of the first body portion, and wherein the channel at the second end of the second body portion forms the inlet.
9. 9. The pressure relief valve of claim 8, wherein the second end is flat.
10. 10. The pressure relief valve of claim 8, wherein the second end is tapered.
11. 11. The pressure relief valve of claim 1, wherein the end of the nozzle is a first end, the nozzle including a second end opposite the first end, wherein the first end is disposed in the second body portion.
12. 12. The pressure relief valve of claim 11, wherein the second end is welded to an inner surface of the second body portion.
13. 13. The pressure relief valve of claim 12, wherein the first material of the first body portion is C12A, the second material of the second body portion is G115, and the nozzle is comprised of nickel alloy 625.
14. 14. The pressure relief valve of claim 12 wherein the inner surface of the second body portion has a first shoulder and the outer surface of the nozzle has a second shoulder that engages the first shoulder.
15. 15. The pressure relief valve of claim 1, wherein the valve seat divides the fluid passageway into an upstream portion and a downstream portion, wherein the upstream portion is defined by an inner surface of the second body portion and by an inner surface of the nozzle.
16. 16. The pressure relief valve of claim 15, wherein the first body portion of the valve body does not form or define the upstream portion of the fluid passageway.
17. 17. The pressure relief valve of claim 1, wherein the second body portion is not directly connected to the first body portion.
18. 18. The pressure relief valve of claim 1, further comprising a spring for biasing the flow control member toward the valve seat.
19. 19. The pressure relief valve of claim 18, further comprising a manual lever for moving the flow control member away from the valve seat.
20. 20. The pressure relief valve of claim 1 wherein the second body portion has a process flange on an outer surface thereof.

Description

Pressure reducing valve for high temperature fluid Technical Field The present disclosure relates generally to valves, and more particularly, to pressure relief valves for high temperature fluids. Background Valves are commonly used in process control systems to control the flow of a fluid (e.g., liquid, gas, etc.) between two positions. Some types of valves are configured as pressure relief valves. The pressure relief valve is designed to protect the system from high temperature/high pressure conditions that could potentially damage other components of the system. Disclosure of Invention Example pressure relief valves disclosed herein include a valve body defining a fluid passageway between an inlet and an outlet. The valve body includes a first body portion having a first side with a first opening and a second side with a second opening. The second opening forms an outlet of the fluid passage. The first body portion is constructed of a first material. The valve body also includes a second body portion coupled to the first side of the first body portion. The second body portion has a passageway aligned with the first opening. The second body portion forms an inlet for the fluid passageway. The second body portion is constructed of a second material having a higher temperature level than the first material. The pressure reducing valve further includes a nozzle disposed in the fluid passage. The nozzle has an end forming a valve seat. The pressure relief valve further includes a flow control member movable relative to the valve seat between a closed position and an open position. Drawings FIG. 1 is a cross-sectional view of an example relief valve having an example valve body that includes an example first body portion and an example second body portion that are composed of different materials. FIG. 2 is an enlarged cross-sectional view of the example valve body of FIG. 1, showing example first and second body portions and an example nozzle. FIG. 3 is a cross-sectional view of an example second body portion engaged with the example first body portion during an example method of assembling the example valve body of FIG. 1. Fig. 4 is a cross-sectional view similar to fig. 3 after the example first and second body portions are welded together. Fig. 5 is a cross-sectional view similar to fig. 4 after machining of the first and second body portions. Fig. 6 is a cross-sectional view of the example second body portion of fig. 5 after the bottom end has been machined in preparation for welding to another component. In general, the same reference numerals are used throughout the drawings and the accompanying written description to refer to the same or like parts. The figures are not necessarily drawn to scale. Rather, the thickness of the layers or regions may be exaggerated in the figures. Although layers and regions with sharp lines and boundaries are shown in the figures, some or all of these lines and/or boundaries may be idealized. In practice, boundaries and/or lines may be unobservable, mixed, and/or irregular. Detailed Description Pressure relief valves, sometimes referred to as safety valves or safety relief valves, are commonly used in process control systems having relatively high pressure and/or high temperature fluids to avoid subjecting the system to overpressure and/or overheating. For example, many power plants and other power plants produce high pressure/high temperature steam to drive turbines to generate electricity. The steam is contained and/or conveyed through various pipes. One or more pressure relief valves may be connected to the steam pipe. The pressure relief valve is a self-actuating device configured to open when the pressure in the system exceeds a preset pressure or level. Thus, if the pressure in the conduit (directly based on temperature) exceeds a preset pressure level, the pressure relief valve opens and vents the high pressure/high temperature vapor to the atmosphere or to a collection system. In this way, the pressure relief valve can prevent damage to the system that may be caused by overpressure and/or elevated temperatures. Currently, the highest steam temperature in coal-fired power stations worldwide is about 600 degrees celsius (°c). This is mainly because the steel for pipelines is composed of P92 martensitic heat-resistant steel with a temperature level up to 622 ℃. Recently, it has been desired to raise the steam temperature of these power stations, for example up to 630 ℃, which can greatly increase the output power. This requires a pipe with thicker walls composed of martensitic heat resistant steel that can be used at metal wall temperatures up to 650 ℃. In conventional pressure relief valves, the inlet portion of the valve body is always exposed to the high temperature fluid in the fluid system. However, these conventional pressure relief valves have a valve body constructed of C12A steel having a temperature rating similar to (but not higher than) that of conventiona