Miscellaneous Manhole and Pipe Accessories

Holeformers

Holeformers are cast into concrete chamber rings to form a void through the concrete wall. Usually this is to allow water to pass from the chamber to the surrounding ground or vice versa.

Key Features

• Clips allow direct attachment to reinforcing wire simplifying mould design
• High quality plastic prevents cracking in cold weather
• Material is resistant to a wide range of chemicals (material datasheet available on request)
• Made with some recycled material

Packers

Packers are used to separate manholes when they are stacked vertically in a yard for storage. They are placed in the tongue and groove joint before the next manhole ring is placed on top. This reduces point to point contact which can cause products to crack, especially when the concrete has not fully hardened.

Key Features

• High quality plastic prevents cracking in cold weather
• Material is resistant to a wide range of chemicals (material datasheet available on request)
• Made with some recycled material

Lifting Keys

The lifting key is a plastic moulding which is cast into concrete covers to provide an accurate void to accept a lifting key.

Key Features

• Creates an accurate, undercut profile in the concrete part
• Simplifies mould design
• Can be supported by steel reinforcement

Unit Alignment Pin

The unit alignment pin consists of two plastic moulded plugs, one is cast into the top of the manhole ring, the other in the bottom at the time when it is manufactured. These form two blind holes. When the rings are to be assembled a stainless steel dowel pin is dropped into the plastic plug in the top of the ring followed by a rubber washer which prevents concrete to concrete contact which may cause cracking. The next ring is lowered on top of the previous ring, the dowel pin in the lower unit is aligned with the plastic insert in the upper unit. This aligns the two rings axially. Depending on the size of the manhole rings three or more pins may be fitted per joint.

Break Off Plug

The range of break off plugs are used to create voids in cast concrete for the purpose of creating lifting holes, step fixing, handle fixing, cable management etc. They are pushed into a hole in the formwork which supports them whilst the concrete is cast. Once the concrete has hardened, the end of the plug which was pushed into the formwork snaps off as the formwork is removed leaving the plug in the concrete ready for use.