Ejectors should not need to be inspected more than once a year except in especially corrosive service. We recommend this be done in the spring because summer condensing water temperatures require optimum ejector performance.

Nozzles and diffusers are the critical parts of an ejector. The inside must be smooth for good operation. Nozzles and diffusers never wear uniformly. Long before there is any measurable wear, the parts are too rough for good operation.

It is possible to tell if the nozzle is clogged simply by unscrewing the nozzle inspection plug in small ejectors. The steam chest (nozzle head) should be removed and the nozzle unscrewed for more thorough inspection. Care should be taken in removing carbon nozzles them from their seats.

Discoloration will not cause poor performance. If the inside of a nozzle is scaled, it should be polished in a lathe with emery paper. If it is rough or cut it should be replaced.

The entrance to the diffuser can be seen after the steam chest (nozzle head) is removed. The diffuser must be removed for closer inspection. If the inside is rough or scaled it can be cleaned in a lathe with emery paper. Care should be taken not to enlarge the diffuser by more than a few thousandths of an inch. The diffuser should be replaced if a smooth surface cannot be obtained.

Make sure the nozzle is screwed in tight and the nozzle gasket is in place. A leak at this gasket will put an extra load on the ejector and cause erosion of the threads.

Make sure other gaskets are in place and tighten all bolts.

JET-VAC carbon-lined diffusers and suction heads cannot be broken by handling, but the faces of the carbon flanges can be scaled or chipped.

Carbon nozzles can be broken, so 1/8” soft gaskets should be used on both sides of the carbon flange. Care should be taken to fit the nozzle into the recess on both the suction head and nozzle head. Nozzle head studs should be pulled up uniformly and carefully.

When cleaning carbon parts, remember that carbon cuts very easily.

In reassembling or replacing parts make sure that the parts of the multi-stage ejectors go in the right stages. The atmospheric stage parts will be marked Z. Parts for other stages will be marked Y, X, W, etc. The highest letter in the alphabet applies to the stage nearest the vacuum system.

Spare nozzles for each stage should be kept in stock. Diffusers are just as susceptible to corrosion and erosion as nozzles, but they are somewhat easier to clean. A spare diffuser is a good investment when the cost of shutdown time is considered.