assure a free-working joint. It is necessary to lubricate every 6 months with the proper grease for this type of joint and the service conditions. Once a year, you should check the flange-to-flange distance of the slip joints. You should check the flanges first when they are cold and next when they are hot. Measuring makes sure that the travel is within the limits shown in the manufacturer's data. A change in slip travel usually indicates a shift in anchorage of a pipe guide, so you must locate and correct the difficulty. You should also inspect annually for signs of erosion, corrosion, wear, deposits, and binding. Then you should repair or replace the defective parts, as required.

The bellows-type joint is checked annually for misalignment, metal fatigue, corrosion, and erosion. You should note the amount of travel between cold and hot conditions. If the joint fails, you should replace the bellows section of the joint.

Expansion loops require little specific maintenance except inspection for alignment and leaks.

The ball joint must be kept adequately packed. You should adjust or replace the gaskets, as required, to correct leaks and obtain a free-working joint. You should always refer to the manufacturer's instructions for doing maintenance work.

The swing joint requires only the normal maintenance required for pipe fittings.

Q8. What are the two categories of radiators?

Q9. The bellows of an automatic air vent contains a liquid with a boilingpoint of what temperature?

Q10. What are the two types of bucket steam traps?

Q11. What is the most common trouble with a thermostatic steam trap?

Q12. The bimetallic strip in a bimetallic-element trap is made of what materials?

Q13. Which steam trap test method uses a crayon?

Q14. What are the two general types of steam- operated water heaters?

Q15. What device controls the quantity of steam required for both types of water heaters?

Q16. What are the five major types of expansion joints?

Q17. A bellows type expansion joint is inspected for misalignment, metal fatigue, corrosion, and erosion how often?