Double Seal Globe Valve – Innovative Solution to Internal and External Leakage
The double seal globe valve is specifically designed to address the common issues of internal and external leakage in medium-temperature and medium-pressure globe valves. This patented product (Patent No.: ZL98 2 26953.6) delivers significantly improved sealing performance compared to conventional globe valves and is widely used in steam systems, oil systems, compressed air systems, and other industrial applications.The main stop valve product names of China Stop Valve Network include:Flange Straight-through Ammonia Globe Valve,GB Cast Steel Flange Globe Valve,GB Stainless Steel Flange Globe Valve,Insulation Globe Valve,High Temperature and Pressure Power Station Electric Globe Valve,Oxygen-specific Globe Valve,Vacuum Isolated Straight-through Globe Valve,Y-type Jacket Insulation Globe Valve.
I. Double Seal Structure – Combining Metal and Soft Seal Advantages
Traditional globe valves face limitations: metal seals offer high pressure resistance but are prone to galling, while soft seals provide tight sealing but are vulnerable to permanent deformation. The double seal structure integrates the strengths of both, utilizing a metal seal as the primary seal and a soft seal as the secondary seal. When minor leakage occurs at the metal sealing surface, the soft sealing ring effectively prevents any leakage, achieving zero leakage. After 10,000 static pressure cycle tests, the structure demonstrated reliable performance with no leakage.
II. Packing Seal Optimization – Enhanced Reliability Through Combined Packing
Conventional single flexible graphite ring packing often suffers from graphite transfer and volume loss, resulting in leakage. By adopting a combination of flexible graphite braided packing for the top and bottom layers and flexible graphite ring packing for the middle three layers, graphite transfer is effectively eliminated, significantly improving sealing reliability. After 10,000 static pressure cycle tests, no leakage was observed at the packing.
III. Sealing Face Hardfacing Material – No. 85 Welding Rod Offers Superior Performance
For medium-temperature and medium-pressure carbon steel globe valves, hardfacing is a critical process. The No. 85 Cr-Mn-N hardfacing welding rod offers excellent galling resistance, a simple hardfacing process, and eliminates the need for preheating and complex heat treatment, reducing production costs. Double seal globe valves hardfaced with this material showed no obvious galling marks on the sealing surfaces after 10,000 static pressure cycle tests, making it an ideal choice.
IV. Prototype Verification – Reliable Performance and Long Service Life
The PN2.5, DN50 double seal globe valve prototype was designed and manufactured in accordance with national standards. Shell tests, sealing tests, and static pressure life tests confirmed that its sealing performance is reliable and its service life far exceeds that of conventional globe valves.
With its innovative structure, the double seal globe valve effectively solves the leakage problems of traditional valves, providing reliable protection for industrial piping systems.
Do you still need to know or purchase the following globe valve products:
