What is a restrained joint pipe?
Restrained joint pipe and fittings are used in pressurized Ductile Iron pipelines to prevent the joints of the line from separating due to thrust forces. Thrust forces generally occur at changes of direction in the line.
How do you restrain a water main?
Thrust blocks, external friction clamps with tie-rods and mechanical joint restraining glands are the most common methods of water main restraints. Restraining glands shouldn’t be used unassisted unless an engineer has calculated the maximum forces and soil samples have been analyzed to determine stability.
What is a mechanical joint restraint?
PVC Pipe — Mechanical. Joint Restrainer. The PVC mechanical joint restrainer eliminates the need for thrust blocking, tie rodding, or harnessing me- chanical joint fittings when they are used with PVC pipe. The key to the restrainer is the specially designed ductile iron, split clamping ring.
What are push on joints?
Push On Joints The most popular, quickest, and easiest-to-assemble joint for Ductile Iron Pipe and fittings in underground applications is the push-on joint. This joint consists of a single rubber gasket placed in a groove inside the socket at the bell end of the pipe.
Are mechanical joints restrained?
Conventional Ductile Iron pipe joints are push-on type joints or bolted mechanical joints, neither of which is restrained.
What is a Megalug?
The Series 1100 MEGALUG® Mechanical Joint Restraints effectively and economically restrain Ductile Iron Pipe (DIP) to mechanical joints above or below ground, for practically any application including valves, hydrants, and pipe.
Where do you put thrust blocks?
Thrust blocks are anchors placed between pipe or fittings and the solid trench wall. They can be constructed from availale lumber if braced properly. However, the recommended thrust blocking is concrete which is calculated to have a compression of 2,000 pounds per square inch.
When would you use a restrained joint pipe?
Restrained joint systems are used because standard slip joint (Tyton®) pipe does not provide significant restraint against separation of the joint created by unbalanced thrust forces.
What is a spigot joint?
A spigot joint is a type of pipe fitting that is inserted into another pipe fitting. The spigot end typically has the same outer diameter as the pipe and is usually fitted into another larger-diameter joint called a bell. Together, these two elements form what is commonly known as a bell and spigot.
What is manual restraint?
Manual restraint means the use of hands or body to immobilize a person’s freedom of movement or normal access to his or her body for more than fifteen continuous seconds. It does not include physically guiding a client during transport or skill training for up to two minutes.
What is restraint force?
Cartwright and Festinger postulate the operation of a “restraining force”, which prevents an observer from responding until he can be reasonably sure that his response will be correct.
How can restraining forces be reduced?
To achieve behavioral change, driving and restraining forces must be “unfrozen”, behavior must be changed in the desired direction and the forces must be “refrozen” to allow the desired behavior to continue. In the case above, the manager can “unfreeze” and reduce restraining forces by providing additional training.