8 Main Parts Of A Rotary Valve
Rotary valves are used in controlling the flow of dry and free flowing particles usually powder and granules in solids handling system. The system usually operates under gravity or vacuum conditions. A material will enter the inlet part and fall into space between the blades. When the blades rotate the material will be carried toward the outlet. The design of the valve should prevent any accumulation or build-up of the material in any of its parts to avoid clogging that will lead to malfunction of the control valve.
Its main components are the following:
1. Housing or Casing - this should be precision machined and made usually of cast iron, stainless steel or aluminium alloy. This is supplied with connecting flanges that are drilled in it. It can have a drop-through, side entry or blow-through design to allow maintenance activities in the future. The inlet or outlet can be round, square or rectangular. Housing designs should be made for high pressure of up to 350 PSIG. It should be very strong capable in holding the whole system for the rotary valve.
2. Endplate - also made of cast iron, stainless steel or aluminium alloy and should be precision machined. A spigot is located within the valve body to to make sure of its concentricity.
3. Rotor with blades - this is mounted on a rotor shaft. The rotor should be supported by bearings. A motor and drive will turn the rotor shaft causing it to rotate inside the housing. The rotor may have open or close ends
4. Blades - may vary in number depending on the design of the control valve. The tips can be adjustable
5. Bearings - should be grease packed and maintenance free. Always check if the bearings are still in good condition during maintenance schedule. Replace defective bearings to avoid problems during your operations.
6. Shaft seals - packing gland with adjustable followers. Must prevent air or other gases and material from leaking in and out of the valve. This is critical part for the system as it will assure that no leakage will happen. Any leak will be bad for the whole system.
7. Drives - should be adjustable. The geared motor should be mounted at the side of the body and must have provisions for drive chain adjustment
8. Electrical controls - always know the electrical parts of the system, this should by isolated and turned off during maintenance activities.
The parts of a rotary valve should be identified for they are the ones to be monitored and checked regularly during maintenance schedules. Refer to how to mainatain a rotary valve for maintenance activities to be conducted.
Make sure that the supplier gives a complete list of spare parts for the valve and assure you the availability of these parts during your need. It is advisable to maintain a safe inventory of spare parts to avoid problems during time of machine troubles. Be familiar with the parts of the valve so that you will know what to do in times of repair and maintenance.