nt of dimensions to determine extent of wear. Part numbers of the various ejector components should be checked to ensure they are in the right unit. Many ejector parts, and complete stages, are physically interchangeable and care must be taken not to mix them.
Keep Spares On Hand: At a minimum, keep at least the following components in stock:
- One steam nozzle for every single nozzle ejector stage
- One diffuser for every stage, at least in sizes through 6 in. — higher, if continuity of service is critical
If continuity of service is important to a process, keep a spare steam nozzle in stock for every size ejector in the system. Spare diffusers are also worthwhile to keep in stock, especially for smaller systems. While it is theoretically possible for the plant engineer to recondition these parts, the practice is not recommended because critical dimensions may be altered.
Since most nozzles are relatively inexpensive they should be considered sacrificial; if wear is evident they may be discarded and easily replaced. A complete Z stage should be kept in stock for important systems in critical operations.
If these simple tips fail, don’t despair. Check the nameplate and call the manufacturer. A condition may be new to you, but chances are the manufacturer has seen it, and corrected it, many times before. Since troubleshooting an ejector system is quite straightforward, suppliers can usually work with you over the phone to get the problem corrected. Experienced service people estimate that at least 50% or more of the troubles referred to them can be solved over the phone.
Of all vacuum-producing devices, the steam-jet ejector is the most forgiving. Occasional inspection, replacement of parts, and adherence to design conditions will keep it operating reliable for many years. Knowledge of these simple procedures for avoiding trouble, and locating it if it does occur, will save time and product in you plant.
Edited by Nicholas Basta