There are several approaches to solving the water hammer problem. This phenomenon is more pronounced in liquid than in gaseous media due to the fact that gasses are compressible and can absorb part of the kinetic energy at the instant the valve is closed. The pressure surge causes a noise which sounds like the pipes were struck by a hammer. If the flow is abruptly stopped by rapidly shutting off the valve, pressure builds up due to the momentum of the moving medium and this causes a short pressure surge. When a valve is open, the medium flows through the valve at a certain speed. Valves can be more or less immune to this problem, depending on their design. Noises are sometimes an early indication of this problem. In a process similar to the one occurring in water heaters, calcium deposits can build up on the armature, causing it to stick and possibly fail. Solenoid valves run at temperatures that can be considerably higher than the temperature of the surrounding air. Limescale can be another cause, especially in systems used with hard water. Foreign matterįinally, foreign matter such as dirt can affect the operation of the valve. An example is a direct operated solenoid valve or a (motor driven) ball valve. In order to avoid this issue, pay attention to the minimum operating pressure differential specification in the solenoid valve datasheet, or use a valve design that does not have minimum pressure differential requirements. If the minimum pressure differential requirement is not met, the valve may not fully open, or may rapidly resonate between the open and closed position, producing audible noise. This is called indirect operated, pilot operated or servo operated. Some valve designs require a minimum pressure differential for the valve to open from the closed position, and to stay in the open state. Indirect operated valves with too low differential pressure Worn armature or damaged springs are often to blame in such cases, and if wear-related issues are suspected, the valve should be examined and serviced by a professional. Internal damage can also produce noisy operation. Some solenoids require speed-control devices for proper operation. Inlet and exhaust tubing should be of sufficient diameter to allow for lower flow rates. Solenoid valves should be chosen having in mind the pressure and flow requirements. Excessive pressure or flow rateĪn excessive pressure differential across a solenoid valve, or a too high flow rate, can cause humming noises in some valve types. If some components are missing, you may find a suitable spare in your distributor’s catalogue. This problem can occur if improper maintenance is performed on the valve.
#12 volt haldex electric solenoid valve manual
It should be verified that all parts are installed according to the manual and that all components are properly tightened. This case might be characterized by a chattering noise. Loose or missing partsĪnother cause can be loose or missing parts in the assembly. This fault can be diagnosed by energizing the solenoid and measuring the voltage across it, making sure that it is within the manufacturer-provided specifications. Undervoltage may cause the solenoid to never fully open, oscillating between the open and closed states, a state which produces abnormal vibrations and an audible hum. One potential cause is undervoltage, caused by improper control signal, faulty control system, bad wiring or control relay malfunction. However, if the noise or vibrations are excessive, this may point to one or more issues. They smoothen out the varying strength of the magnetic field by storing magnetic energy while the current is at its peak, and releasing it when the AC current is near to zero. Most solenoid valves include a shading ring, usually made from copper, which is used to buffer the magnetic energy created by the current flowing through the solenoid. They are the result of alternating current producing a varying magnetic field which acts on the armature of the valve. Soft buzzing and slight vibrations are normal in some types of AC solenoid valves. Solenoid valves operating on alternating current may produce a noise accompanied by vibrations.