/ Hammer Union Seals
Standard Service Nitrile (NBR) Hammer Union Seals for Figure 1502 Unions
Our Hammer Union Seals are engineered to provide leak-free performance in Weco® style union connections used in high-pressure flowlines. Manufactured from high-modulus elastomers and reinforced with anti-extrusion backup rings (Brass or Stainless Steel), these seals withstand the extreme pulsating pressures and abrasive fluids found in hydraulic fracturing and cementing operations.
Technical Specifications
- Working Pressure Ratings: 1,000 PSI to 22,500 PSI (depending on union rating)
- Durometer: 80-95 Shore A
Applications
- Hydraulic Fracking: High-pressure sand and proppant injection lines.
- Flowback Operations: Managing post-frac fluids and gases.
- Choke & Kill Manifolds: Safety-critical well control connections.
- Mud Lines: Circulating drilling mud systems.
- Acidizing & Cementing: Handling abrasive cement slurries and acid fluids.
Standard Service Nitrile (NBR) Hammer Union Seals for Figure 1502 Unions
1. Executive Summary: The Industry Standard for 15K PSI
In the high-stakes environment of hydraulic fracturing and well stimulation, the Figure 1502 Hammer Union is the global standard for connecting high-pressure flowlines. Our Standard Service Nitrile (NBR) Seals are engineered to be the critical safety barrier within these connections.
Manufactured from a proprietary, high-modulus Nitrile Butadiene Rubber (NBR) compound, these seals are designed to withstand the punishing conditions of Standard Service applications—including water, drilling mud, fracking fluids, and sand slurries—at working pressures up to 15,000 PSI (1,034 Bar). Each seal is reinforced with a precision-machined backup ring to prevent gap extrusion, ensuring operational integrity during pressure spikes and pulsation.
2. Technical Deep Dive: Anti-Extrusion Technology
The Mechanism of Failure
At pressures exceeding 10,000 PSI, elastomer seals behave like liquids. Without reinforcement, the rubber would be forced into the tiny clearance gap between the male and female union subs. This phenomenon, known as Gap Extrusion, leads to “nibbling” or shredding of the seal, resulting in catastrophic washout.
The Composite Solution
Our Figure 1502 Seals utilize a dual-component architecture:
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Primary Seal (Elastomer): 90 Durometer NBR provides the static seal and initial low-pressure seating. It features high abrasion resistance to survive the passage of proppants (frac sand).
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Secondary Support (Backup Ring): A rigid backup ring (Brass or Stainless Steel) sits at the heel of the seal. As pressure builds, the elastomer compresses against the ring, which bridges the extrusion gap, effectively containing the rubber and maintaining the seal’s structural integrity up to burst pressures exceeding 22,500 PSI.
3. Comprehensive Technical Specifications
| Technical Parameter | Specification Data | Test Standard |
| Compatible Union | Weco® Style Figure 1502 | – |
| Material Type | Nitrile Butadiene Rubber (NBR / Buna-N) | ASTM D1418 |
| Service Classification | Standard Service (Non-Sour) | NACE MR0175 (Compliant for non-exposed) |
| Durometer (Hardness) | 80-85 Shore A (±5) | ASTM D2240 |
| Tensile Strength | > 2,100 PSI (14.5 MPa) | ASTM D412 |
| Elongation at Break | > 200% | ASTM D412 |
| Compression Set | < 25% (22 Hours @ 100°C) | ASTM D395 Method B |
| Working Pressure | 15,000 PSI (1,034 Bar) | CWP (Cold Working Pressure) |
| Test Pressure | 22,500 PSI (1,551 Bar) | – |
| Operating Temperature | -20°F to +250°F (-29°C to +121°C) | Continuous |
| Abrasion Resistance | Excellent (Din Abrasion < 150mm³) | DIN 53516 |
| Color | Black (Elastomer) | Visual ID |
4. Field Applications
These seals are the “workhorse” of the completion industry, found on:
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Missile / Manifold Trailers: Main discharge lines connecting the high-pressure pumps to the wellhead.
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Frac Iron: Pup joints, Tees, Ells, and Crosses.
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Plug Valves: Stem and body sealing for 2″ and 3″ plug valves (1502 ends).
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Cementing Heads: Withstanding the abrasive nature of high-density cement slurries.
5. Compatibility & Interchangeability
Our seals are dimensionally guaranteed to fit all major 1502 Union manufacturers, including:
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FMC Weco®
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SPM® (Weir)
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Kemper Valve & Fittings
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Anson®
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Guiberson®
⚠️ SAFETY WARNING: These seals are NOT for use in Sour Gas (H2S) environments. Exposure to Hydrogen Sulfide will cause NBR to harden and crack (embrittlement). For H2S service, please select our HNBR or Viton® seals.