QF2A cylinder valve
DSW, located in Ningbo City, China, is an industry-leading manufacturer of high-pressure gas cylinders and valves. Since 2000, it has produced over 20 million reliable cylinders that are in service worldwide.
DSW devotes itself to research and development for cylinders and valves to provide top-quality products suitable for beverage, scuba diving, medical use, and fire safety applications.
QF2A cylinder valve
O-ring Seal Valves
The valve has a two-piece spindle, a soft seating mechanism, and a brass body.
These valves feature a non-rising upper spindle and a threaded lower spindle. The upper spindle utilizes O-rings to establish a seal. Notably, the top spindle is designed to fail first, enabling valve maintenance and retrieval of package contents in the event of a failure, even when the cylinder is fully pressurized. These valves are available in key, toggle, handwheel, and handle operation variants.
The upper spindle is paired with a handwheel for hand-operated functionality. This design prevents users from applying excessive torque to operate the valve, safeguarding the operating mechanism and ensuring an extended cycle life.
In key-operated valves, the upper spindle is typically constructed from stainless steel to withstand the high torques encountered in field applications.
These valves offer enhanced ease of operation compared to packed valves, as they do not exert packing load on the upper spindle. Consequently, they are suitable for a wide range of pressure and non-corrosive gas applications where low torque operation is desired.
Diaphragm Seal Valves
The valve is handwheel operated and features a two-piece spindle design with a soft seating mechanism.
Brass, Stainless steel
These valves incorporate diaphragms for gland sealing, providing them with exceptional leak integrity. The valve’s gland nut securely fastens to the valve body, pressing the outer edges of the diaphragms against a ledge within the valve body to establish a reliable seal. The lower spindle assembly within a spring operates without threads or lubrication and is pushed away from the seat when the valve is opened. The upper spindle is threaded into the gland nut. The valve’s flow capacity is restricted by the stroke of the diaphragm, effectively regulating the flow through the valve.
This design is particularly well-suited for toxic, pyrophoric, and high-purity gas applications. However, it is essential to note that these valves are limited to cylinder pressures up to 200 bar due to the substantial torque required to close the valve, which involves overcoming the cylinder pressure multiplied by the diaphragm’s area in addition to the force exerted by the spring.