Leakage in hammer union connections is more than a nuisance; it's a serious safety hazard, an environmental risk, and a major source of non-productive time (NPT) on the rig. While the hammer union itself is a robust and trusted component, its performance is entirely dependent on a single, often overlooked part: the seal. Standard seals can extrude, crack, or degrade when exposed to high-pressure H₂S, methane, and rapid pressure cycles, leading to frequent and costly replacements. The solution isn't tightening the hammer nut further—it's upgrading to engineered hammer union seals specifically designed for the brutal conditions of oilfield fluid systems.

JST offers two lines of hammer union seals, one from elastomer, another one from elastomer reinforced with anti-extrusion ring which is normally used for high pressure.

JST's hammer union seals have a variety of configurations and materials to choose from, including NBR, HNBR and Viton.

For cold weather applications we offer both a low temperature rated (-50°C to +120°C) NBR and HNBR elastomers.

In addition to standard molded rubber seals, the brass or stainless steel anti-extrusion ring can also reinforce hammer union seals. It can fully meet the specific performance requirements of your demanding operating environment.

Advantages:

• Good oil resistance, corrosion resistance, wear resistance and aging resistance
• A range of elastomer hardnesses from 70 to 90 durometer
• Widely used in cementing, fracturing, acidizing, testing, and choke-and-kill lines

Selecting the correct seal involves more than just matching size and pressure rating. It requires expertise in material compatibility with your specific wellbore fluids, understanding the pressure and temperature profiles, and considering the cycle frequency. As a trusted seal manufacturer, we provide more than just parts; we provide application expertise.