Stainless Steel Flanged Compressors Liquid Nitrogen Seal Anti-Freeze Cryogenic Globe Valve

Product Description

The materials of low temperature valve body, valve cover and other pressure parts are usually made of tough materials with good low temperature strength, and factors such as weldability, machinability, stability and economy must also be considered. When designing, three low temperature grades of -46°C, -101°C and -196°C are commonly used. -46°C low temperature grade generally uses low temperature carbon steel, -101°C and -196°C low temperature grade generally uses 300 series austenitic stainless steel, which has moderate strength, good toughness and good processing performance.



Suitable for the transport of cryogenic and ultra-cryogenic media, such as liquid nitrogen.
Good shutoff capability.
Moderate to good valve throttling capability.
Shorter stroke (compared to a gate valve).
Easy to machine or resurface the seats.
Can be used as a stop-check valve.
Can only be used for one-way fluid flow.
Good sealing performance,small friction between sealing face and life long.



The working medium of the cryogenic valve is not only low in temperature, but also has high permeability, which determines many special requirements for valve materials. The mechanical properties of steel at low temperature are different from those at normal temperature. In addition to strength, the important index of low temperature steel is its low temperature impact toughness. 
The low temperature impact toughness of the material is related to the brittle transition temperature of the material. The lower the brittle transition temperature of the material, the better the low temperature impact toughness of the material. Metal materials with body-centered cubic lattice such as carbon steel have low temperature cold brittleness, while the impact toughness of metal materials with face-centered cubic lattice such as austenitic stainless steel is basically not affected by low temperature.






No matter what type of globe valve you have, there are several key parts that all globe valves contain: body, seat ring, cage, bonnet, stem, plug (disk), yoke, yoke nut, back seat, packing, and valve Actuator.
 

Body

The body is the main structure of the valve that keeps everything together. This part contains all internal parts of the globe valve to allow the control of the substance that needs regulation. The opening of the body contains ports (usually two or three ports) to enable the movement of the fluid to the inside or outside of the globe valve.

Seat Ring

The seat is among other globe valve parts that seal the space between the disk/stem and bonnet. The seat ring can be screwed into the valve or torqued. The seat is also known as a seat ring and provides a shutoff surface that's stable and also replaceable. Seat rings can hold the cage firmly to the body of the valve.

Bonnet

The bonnet is one of the outer globe valve parts that's connected to the body to provide a leak-proof closure. There are different bonnet types such as bolted, screw-in, or union bonnet that are used in different globe valves. Each of these bonnet types has its own advantages. For example, the union bonnet not only adds strength to the body but is also great for applications that need regular cleaning or inspection. The screw-in bonnet with its simple design offers a pressure-tight seal. And the last bonnet type, the bolted bonnets that are attached with bolts are great for higher pressures.

Stem

The stem is part of the globe valve that connects the disk to the handwheel or the valve actuator to transmit the actuation force. Since it connects the actuator to the parts inside of the globe valve, it is considered as one of the critical globe valve parts. If the valves are controlled by actuators, the stem is smooth but for the manual valves, they are threaded.

The ends of smooth steam are threaded allowing the connection to the actuator and the plug. A wearable packing surrounds the smooth stem to prevent leaking material from the valve. So, the packing should be replaced regularly in the maintenance period. The stem can withstand a large amount of compression force in the closure state. And when the valve is opening, it has high tensile strength.

Plug (Disk)

The plug or the disk is among the essential globe valve parts. It moves perpendicular to the seat and its movement can block or free the flow since it works as a moveable physical barrier. When the valve is closed, the plug sits against the seat to block the flow and when it sits above the seats. it enables the flow of the material.

Different disk arrangements have been designed for globe valves such as composite type, ball type, and needle type. The composite disk can provide a better shut-off, while the ball type is used for low-temperature and low-pressure systems. The needle disk has the advantage of providing a better throttling compared to the other two.

 

 

 

DN mm	Flange drilling	L mm	H mm	H3 mm	F mm	F1 mm	F2 mm
40	PN10/16	240	200	263	14	16	30
50	PN10/16	250	209	292	14	16	30
65	PN10/16	270	243	336	17	20	34
80	PN10/16	280	282	382	17	20	34
100	PN10/16	300	319	429	19	22	34
125	PN10/16	325	346	471	19	22	34
150	PN10/16	350	403	493	19	22	34
200	PN10/16	400	490	660	24	28	34
250	PN10/16	450	664	864	27	31	47
300	PN10/16	500	740	968	27	31	47
350	PN10/16	550	947	1207	32	37	55
400	PN10/16	600	959	1249	32	37	55
450	PN10/16	650	958	1278	32	37	55
500	PN10/16	700	958	1316	32	37	55