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NIKE Running ShoesNIKE Running Shoes
ssibility of a leak developing during field reassembly is eliminated. Also, no parts can be lost or misassembled.
If a valve is equipped with a manual-opening stem, be sure to open it during a nitrogen brazing purge and subsequent evacuation. Also, in some designs, having an elastomer or plastic seat material out of contact with the hot valve body during brazing provides an added margin of safety from heat damage.
For an ac coil that is not installed on a valve, never apply power for more than a few seconds. As noted earlier, current draw is greatly influenced by the amount of iron in the solenoid core. When the coil is uninstalled, there is no iron and current can be as much as four times' normal.
It is recommended that valves not be installed with the plunger enclosing tube (coil tube) angled down below the horizontal. The reason is that system debris can collect in the tube, preventing proper magnetic contact between the plunger and the stationary pole piece in the top. This can cause coil buzz and excessive current draw.
Again, the valve insNIKE Running Shoes truction sheet usually gives troubleshooting tips, but here are some causes of trouble that may be more elusive.
Under-voltage as well as over-voltage can cause coil burnout, the same as a motor. Also, pressure differentials that are too high for the valve to open against can cause coil burnout, because current draw tends to remain near the inrush value.
Make sure that the design pressure drop is always at abercrombie outlet onlineleast equal to the minimum differential that the valve is rated for.
