Grayloc® Closure Systems
Providing easy, quick, and safe access.
Our Closure Systems provide simpler and faster access to pressure vessels and other pressurized equipment by combining our Grayloc Clamp Connector with clamp supports and a hinged door. Suitable for use in extreme temperatures and pressures, the customizable systems can be oriented vertically or horizontally to meet your operational needs.

Well-suited for large diameter applications

Enable safe, rapid, and frequent access

Eliminate fugitive emissions

Technical Specifications
Nominal pipe size | 6 to 36 in, larger sizes available upon request |
Design pressure rating | From full vacuum up to 60,000 psig |
Design temperature range | -423 to 1700°F / -253 to 927°C |
Hub | Nickel alloys, carbon, low-alloy, stainless and duplex stainless steels |
Seal ring | Nickel alloys, low-alloy, stainless and duplex stainless steels |
Bolting | Nickel alloys, carbon, low-alloy, stainless and duplex stainless steels |
Trunnion | Nickel alloys, carbon, low-alloy, stainless and duplex stainless steels |
Support plate | Nickel alloys, carbon, low-alloy, stainless and duplex stainless steels |
Drive screw | Nickel alloys, low-alloy, stainless and duplex stainless steels |
Hinge pin | Nickel alloys, carbon, low-alloy, stainless and duplex stainless steels |
ASME B31.1, Power Piping |
ASME B31.3, Process Piping |
ASME B31.4, Pipeline Transportation Systems for Liquids and Slurries |
ASME B31.8, Gas Transmission and Distribution Piping |
ASME B31.12, Hydrogen Piping & Pipelines |
ASME Section I |
ASME Section VIII Div. 1 |
ASME Section VIII Div. 2 |
ASME Section VIII Div. 3 |
API 6A: Specification for Wellhead and Christmas Tree Equipment |
Product Documents
Optional Features Our self-contained, ready-to-install closure assemblies can be customized to meet your project and access requirements.
-
Seal ring retention system
-
Pressure sensor
-
Temperature sensor
-
Safety interlock systems
-
Zero pressure verification (vent valve)
-
Automated opening and closing
-
Sight glass
-
Bolt shrouds
-
Adjustable hinges
-
Hydraulic nuts for bolt tensioning
-
Single drive screw (remote clamp layout)
-
ASME code stamped
Typical Applications
