REMKO RT 080, Руководство оператора, Страница: 11 / 40

10
Allow an over-heated pump to cool before servicing. Do not remove plates,
covers, gauges, or fittings from an overheated pump. Liquid within the pump
can reach boiling temperatures, and vapour pressure within the pump can cause
parts being disengaged to be ejected with great force. After the pump cools,
drain the liquid from the pump by removing the casing drain plug. Use caution
when removing the plug to prevent injury to personnel from hot liquid.
If the installation involves a flooded suction such as below-ground lift station. A pipe
union and manual shut-off valve may be installed in the bleed line to allow service of the
valve without shutting down the station, and to eliminate the possibility of flooding. If a
manual shut-off valve is installed anywhere in the air release piping, it must be a full-
opening ball type valve to prevent plugging by solids.
If a manual shut-off valve is installed in a bypass line, it must not be
left closed during operation. A closed manual shut-off valve may
cause a pump which has lost prime to continue to operate without
reaching prime, causing dangerous overheating and possible
explosive rupture of the pump casing. Personnel could be severely
injured.
DANGER!
When properly installed and correctly adjusted to the specific hydraulic operating
conditions of the application, the Automatic Air Release Valve will permit air to escape
through the bypass line, and then close automatically when the pump is fully primed
and pumping at full capacity.
Theory of Operation
Figures 3 and 4 below show a cross-sectional view of the Automatic Air Release Valve,
and a corresponding description of operation.
6. AUTOMATIC AIR RELEASE VALVE
During the priming cycle, air from the pump casing flows through the bypass line, and
passes through the Air Release valve to the wet well (Figure 3).
When the pump is fully primed, pressure resulting from flow against the valve
diaphragm compresses the spring and closes the valve (Figure 4). The valve will
remain closed, reducing the bypass of liquid to 3.8 to 19 litres per minute, until the
pump loses it's prime or stops.
Figure 3. Valve in Open Position Figure 4. Valve in Closed Position