ASTM A105N Trunnion Ball Valve, API 6D, 8*6 IN, CL1500, RTJ

Product Name: ASTM A105N Trunnion Ball Valve, Reduced Port
Design Standard: API 6D
Body Material: ASTM A105N
Size: 8*6 Inch, DN200*DN150
Pressure: Class 1500 LB, PN250
Operation: Worm Gear
End Connection: RTJ Flanged
Face to Face Standard: ASME B16.10
Test & Inspection Standard: API 598
Certificates: TA-Luft, ISO 15848-1, API 622, ect

Product Range

Body Materials: 
Carbon Steel: ASTM A105, A105N
Stainless Steel: ASTM A182 F304/F304L, F316/F316L
Gasket & Packing Material: Graphite, PTFE
Size Range: 2-48 Inch, DN50-DN1200
Pressure Range: Class 150-2500 LB, PN16-PN420
End Connection: Flanged (RF, FF, RTJ)
Temperature Range: -29°C to 550°C
Medium: Water, Oil, Gas, Acids, ect

For 6D ball valve design, we focus more on the details, such as deep control over the performance of non-metallic materials. We are well aware that many so-called explosion-proof O-rings used in ball valves in China are not truly explosion-proof. Most valve manufacturers only use "hardness compliance" as the material acceptance criterion, which is not enough to determine whether an O-ring is genuinely explosion-proof.

Many O-ring suppliers understand this. As long as the hardness meets the required range, they supply the product. In reality, truly explosion-proof O-rings require low-temperature, long-duration vulcanization. However, this slows down their production. To improve efficiency, they increase the vulcanization temperature and shorten the time, compromising quality.

In high-pressure applications, if the O-ring is only hard but lacks toughness, excessive rigidity leads to stress concentration on the sealing surface and may cause cracking. If it is tough but not hard enough, extrusion deformation and sealing failure can occur. What you mentioned as "both hard and tough" is actually about balancing Shore hardness (to provide rigid support) with elongation at break and rebound resilience (to resist deformation). This is crucial for preventing media penetration and cracking under extreme conditions. When media such as gas or flammable liquids enter micro-cracks in the rubber, high pressure can create a "splitting effect", resulting in seal failure or even serious safety incidents.

Our deep involvement, knowing applications better than the suppliers and understanding materials better than the users, has allowed us to establish our own technical voice and authority.

Therefore, in many high-pressure valves, O-ring seal failure at the valve seat is common. Many engineers choose to add backup rings to prevent extrusion and tearing. However, the real issue often lies in the O-ring itself. When it has toughness but lacks hardness, it indicates that the material is not a qualified explosion-proof compound.

We've tested such O-rings at China University of Petroleum (Beijing) for explosion-proof performance. Although they met hardness requirements, their explosion resistance failed completely. Under high-pressure methane gas impact, the O-rings developed full-surface cracking. This poses significant safety risks for pipeline ball valves.