Welcome to RMI Engineering Corporation

Pipes &
Connection Systems

Joints & Joint Materials: Joint means connection between the adjacent ends of two components including the means of sealing. There exist different types of joints, for example:


Joints & Joint Materials:

Elastomeric joint ring:
An annular ring used to provide a watertight seal between pipe spigot and socket in a flexibly jointed pipeline.

Flexible joint:
A type of joint using an elastomeric joint ring to provide a watertight seal whilst permitting a specified amount of movement between adjacent pipes.

In wall joint:
A type of joint where the socket is made within the wall of the pipe, usually referred to as a rebated, ogee or tongue and groove joint.

Ogee Joint:
See 'Rebated joint'.

Rebated joint:
A joint made within the wall thickness of a unit, including ogee and tongue and groove joints.

Steel banded joints - steel collar:
Type of joint where the socket is made within the wall thickness of the pipe by means of an integral steel collar. Used for jacking pipes.

Tongue and groove joint:
See 'Rebated joint'.


Pipe Liners:

Liners in metal pipes electrically insulate the fluid from the pipe, allowing accurate flow measurement. No single liner technology can be used for the entire range of nominal diameters from DN2 to DN2000, and each customer application is unique. 4 different liner materials:

rubber, polyurethane (PU)

and two different fluoro plastics – polytetrafluoro ethylene (PTFE) and perfluoroalkoxy (PFA).

Rubber liner exhibits good chemical resistance against water and alkaline solutions, but is not suited to oils or acids and fails to meet the hygienic requirements of the food and pharmaceutical industries.

PFA liner is resistant to chemical and high temperatures (up to 180°C).


Pipe fittings:

Pipe fiittings cover many components that connect pipe ends for in-line, offset, multi-port, and mounting configurations. Pipe fittings are manufactured from a wide variety of materials for the transport of an equally wide variety of solids and fluids. Fitting cross sections are often, but not necessarily, circular in shape to mate with the pipe sections they are connecting; systems are typically configured with straight sections connected by fittings or specially-formed connections and joints. They are used in pressurized applications and non-pressure applications such as drain, waste, and vent (DWV) systems.  

Common types of pipe fittings include adapters, bulkhead fittings, caps, compression fittings, rigid couplings, flexible couplings, cross or 4-way fittings, 90 degree elbows, 45 degree elbows, reducing elbows, end bells, expansion joints or couplings, ferrules, flanges, nipples, offset fittings, plugs, concentric reducers, eccentric reducers, returns or traps, side outlet elbows, side outlet tees, standard tees, reducing tees, bullhead tees, unions, standard wyes, and reducing wyes.  

Common materials of construction for pipe fittings include ABS, aluminum, brass, bronze, carbon or graphite, ceramic or ceramic lined, clay or vitrified clay, concrete, CPVC, EPDM, fiberglass or composite, fluororesin (PFA), glass or glass lined, gray or cast iron, ductile iron, lead, neoprene, rubber or elastomer, nylon or polyamide, polyethylene (PE), polypropylene (PP), PTFE or PTFE lined, polyvinyl chloride (PVC), carbon and alloy steel, stainless steel, titanium, and zirconium