S-500 Threaded Quick
Opening Closure
Triple S Solutions supplies the Stark S-500 Threaded Quick Opening Closure, historically the most widely used closure style in the oil and gas industry.
Manufactured in diameters from 2 inch to 52 inch (DN50 to DN1300) and pressure series 150 through 2500, the S-500 is designed as a robust, cost-effective solution for pipeline and pressure vessel access. Stark Solutions enhanced the proven threaded design to improve operator control, reduce hammering during opening, and strengthen overall safety performance.
Certified to ASME B31.3, B31.4, B31.8, and CSA Z662 Category I/II, with ASME Section VIII Div. 1 U-Stamp options available, the S-500 delivers reliable sealing and long-term durability across a wide range of applications.
For full sizing, pressure ratings, and configuration details, download the product documentation below.
KEY FEATURES
- Threaded quick opening closure design
- Sizes 2” to 52” (DN50 to DN1300)
- Pressure series 150 through 2500
- Certified to ASME B31.3 / B31.4 / B31.8 / CSA Z662
- Cap designed per ASME BPVC Section VIII Div. 1, U-Stamp compliant
- Pressure Alert Valve (PAV) per UG-35 of ASME BPVC VIII Div. 1
- Modified ACME thread engagement for enhanced safety
- Flat metal-to-metal sealing surface for optimal O-Ring performance
- NACE MR0175 compliant materials
- Operating temperature range -50°F to +400°F (-45°C to 204°C)
- Bidirectional hinge design allows cap opening to left or right
- Opening tools supplied for controlled operation
- Flanged closure and welded connection options available
Performance Advantages
Enhanced Thread Engagement Safety
The modified ACME thread design maintains over 90 percent thread engagement even after the closure seal is broken. This prevents the cap from dislodging should residual pressure remain in the vessel or pipeline.
Pressure Alert Protection
The Pressure Alert Valve must be removed before the cap can rotate, adding a mandatory safety step in compliance with ASME Section VIII Div. 1. This design provides clear warning of residual pressure prior to opening.
Sealing Performance
Metal-to-metal contact between the cap and hub ensures full compression of the O-Ring groove. The threaded design aids in consistent seal compression, while the use of industry standard O-Rings supports cost-effective maintenance and replacement.
Operator-Focused Opening Control
Supplied opening tools reduce the need for hammering and improve leverage during operation. Larger closures incorporate ratchet tools and enhanced hinge guidance systems to improve control and ease of use.
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