Split-Ring Closures


Easy Access to Pressure Vessels

Parr reactors and pressure vessels are equipped with a unique split-ring cover clamp which adds greatly to the convenience of the equipment and the ease with which it can be handled. This is an exclusive Parr design (Split-Ring U.S. Patent No. 2625296) which allows easy access to a pressure vessel without using a heavy screw cap, cumbersome cover clamps, or a wide flange for moveable bolts. Instead, the head is clamped to the cylinder by either a Type 4140 Steel or a Type 316 Stainless Steel ring which has been split into two sections. These sections slide into place from the sides without interfering with any fittings attached to the head.

Self-Sealing and Compression Bolt Designs

For reactors and vessels in which a self-sealing O-ring is used as the main head seal, there are no compression bolts in the split-ring sections. The vessel is closed by simply sliding the two ring sections into place and locking them with either an encircling drop band or with attached, quick-opening latches. This convenient closure can be used on most small and mid-sized Parr reactors and pressure vessels, provided the intended operating temperature does not exceed the allowable working temperature limit for the O-ring seal. Self-sealing O-rings are not recommended for low pressure applications. SeeSelf Sealing O-Ringsfor additional information.

Split-ring closures for reactors with PTFE, flexible graphite, metal or other contained, flat gaskets have a set of compression bolts in the rings which must be tightened to develop the compressive force required to seal the gasket. These split-rings are locked together with either a drop band or quick opening latches.

With either style, the closure parts come completely away from the vessel so that the head with all of its fittings can be lifted from the cylinder or the cylinder can be dropped away without disrupting any attached fittings. When compression bolts are used, they are simply tightened or loosened, they are never completely removed from the split-ring or drop band. This saves time both in opening and closing the vessel and in looking for lost parts.

Hinged Split-Rings

Hinged split-rings offer a safe and convenient solution for opening larger fixed head vessels. With this design, the split-rings swing out of the way to allow easy access to the vessel. Hinged split-rings come standard on fixed head vessels 3.75 Liters or larger and can be customized to other sizes.

Split-ring closures add many attractive features to Parr reactors and pressure vessels.

  • The reactor or vessel can be opened and closed without disturbing any connections or fittings attached to the head.
  • The full inside diameter of the vessel is exposed when the head is removed.
  • A maximum area is exposed on the head for attaching valves and fittings.
  • There are no cumbersome bolt flanges or threaded studs to interfere with operations.
  • No delicate threads on the cylinder to gall or to be damaged in handling.

Screw Cap Closures

Parr uses screw cap closures on small vessels where enough sealing force can be developed by simply tightening the main screw cap. This design can be made more compact than the split-ring closure and is used primarily on general purpose vessels with volumes of less than 100 mL.

We'll help you configure a system that meets all of your research needs.