Chapter 16 book one piping expansion support and insulation

Question 1

Expansion Bends

Answer 1

This is one method to accommodate expansion and long pipe lines. The increase in length due to expansion is taken up by flexing or springing of the bins, which are U-shaped expansion Benz or preferred for high-pressure work, as there’s no maintenance involved in little likelihood of leaks developing, but they do require large amounts of extra space and add friction loss due to the extra amount of pipe the fluid hast to pass through.

Question 2

Two types of expansion joints

Answer 2

Slip type and the corrugated tape

Question 3

Slip expansion joint

Answer 3

Essentially, this is a pipe inside a pipe that has packing between the two pipes. It is also fitted with grease fittings to provide lubrication so the pipe can slide within the other pipe. If only one expansion joint is used it should be place in the middle of the pipeline And the joint should be anchored if several expansion joints are used anchors may be placed midway between the joints or at the joints themselves. These are suitable for medium to low pressures and requires less space than the expansion bends but it does require maintenance.

Question 4

Corrugated expansion joints

Answer 4

Either a regular corrugated expansion joint or a bellows type expansion joint. The regular corrugated is a simple design suitable for only low pressure and is available with either flanges or welding ends. The bellows type is suitable for pressure up to 290 psi. They also have the advantage of requiring less space than expansion bins and they do not require parking like the slip type but the amount of movement provided by the bellows or corrugations, is less than the slip expansion joint.

Question 5

Two types of pipe hangers

Answer 5

Strap hanger which clamps to the pipe and does not allow relative movement between the pipe and the hanger

Roller hanger, which allows for axial movement of the pipe, as the pipe simply rests on the rollers

Question 6

Piping insulation

Answer 6

When piping carries cold substances insulation will prevent sweating of the pipe and consequent, dripping and corrosion. A good insulation will have a low conductivity, the lower the value of K which is conductivity the better.

Question 7

Pipe insulation, materials and application

Answer 7

Foamed plastic are generally used in low and lower intermediate service temperatures that range from -183°C to 150°C

Refractory fiber has the highest temperature reading at 1650°C and it is noncombustible

 Sectional pieces of insulation are usually assembled over the pipe and bound with wire or light metal bands painting. The pipe will provide a vapor barrier protecting the pipe from corrosion and the insulation from becoming wet as the wet insulation loses its insulating value for odd shaped, fitting, such as valves or flanges insulation may be applied in the form of a paste.