Mechanical seal for water pumps, also known as end face seal, is defined in the relevant standards as a device that prevents fluid leakage by maintaining contact and relative sliding between at least one pair of end faces perpendicular to the rotation axis under the action of fluid pressure, compensation mechanism elasticity, and auxiliary sealing.
During the entire installation process of the mechanical seals for water pumps, components should be wiped with clean cloth or cotton yarn, especially the sealing surface, using clean, soft gauze, degreased cotton, and the like.
Before disassembly, check whether the components are damaged and whether the spraying coat on the spring is falling off.
Carefully inspect the sealing surfaces of the rotary ring and the stationary seal ring to make sure there are no scratches. When dismantling them, apply a layer of clean machine oil or turbine oil on the sealing surface.
When adjusting the components of the mechanical seal, pay attention to the compression of the spring. When moving the rotary ring, do not let the "O" shaped sealing ring curl inside the rotary ring at an angle. The allowable leakage rate is about 5 drips per minute.
When assembling mechanical seals parts, be careful, especially with plastic products. Do not use hammers, flat shovels and other tools to knock around to avoid damaging the sealing element. If it is difficult to disassemble due to dirt, do not force the assembly but rinse and clean first, and then gradually assemble.
When dismantling the mechanical seal, be sure not to let the whole machine tilt, and evenly tighten the spring seat fixing screws.
The pressure-boosting system structure of the mechanical seal includes an outlet, a fixed flange, a pump body, a booster, a motor rotor, a lifting ring, a protective cover, a water pump, a fixed base, a base, a reinforcement, a control valve, and fasteners. The outlet is connected to the fixed flange, and the pump body is connected to the booster. The booster is composed of an inlet, a water pipe, a negative pressure chamber, a balanced fixing plate, and a fixing bracket. The inlet is connected to the water pipe, and the water pipe is connected to the negative pressure chamber. The negative pressure chamber is balanced through the balanced fixing plate, and the fixing bracket is connected to the pump body. The protective cover is connected to the water pump, and the water pump is connected to the fixed base. The fixed base is tightly connected to the base, and there are reinforcements on the base. The fastener is fixedly connected to the base. The mechanical seal with a balanced tank is a pressure transmission mechanism used for double end face mechanical seals to solve the problem that some existing circulating water pumps cannot overcome the system resistance. When the flow rate of the circulating pump does not change, once the head of the circulating pump increases, the power of the motor equipped with the circulating pump will greatly increase, and the operating cost of the equipment will also increase accordingly.
Since the pressure area on the upper end of the piston body of the mechanical seal is less than that on the lower end of the piston body by an area of a piston rod, the oil pressure of the mechanical seal increases inversely with the pressure area on both ends to ensure the sealing condition. When designing the ratio of pressure areas on both ends of the piston, it should be calculated based on the pressure difference between the sealing chamber and the kettle. The piston rod is equipped with a spring to adjust the amount of spring compression, so that the spring force just offsets the frictional force of the O-ring on the piston against the cylinder wall, reducing the error between the calculated pressure difference and the actual one. In addition, the piston lifting also has the function of indicating the liquid level in the balance tank. When the sealing liquid needs to be replenished due to leakage, a manual pump can be used to add the sealing liquid. When using it, pay attention to keeping the piston in the lower part of the balance tank so that the piston has room to move upwards.