I. Overview I plant development and production of 3D-SY750 Series electric test pump, is currently China's current two-cylinder, four-cylinder motor test pump replacement. The product is small, compact, stable, safe, reliable, full-featured, high traffic, high efficiency, and the wide range of applications, supporting strong, simple operation. For all the need for pressure burst test and the strength test sites of various types of pressure vessels, boilers, pipe fittings, lockable test pressure values ??as needed, and can be automatic packing. Pump transport medium is generally room temperature water can also be used emulsion, rust and water viscosity similar to water neutral oil. Second, the main structure and working principle of the machine is mainly composed of high pressure reciprocating pump, pressure relief valve (40Mpa above specifications is no such component), check the pressure relief valve. 1, high-pressure reciprocating pump: The pump is a horizontal three plunger pump, driven by a motor, into power end and fluid end. (1) The power end :( Figure 1) consists of a pulley, crankshaft, connecting rods and other components. Motor through the pulley drive and slow down, drive the crankshaft rotation, by the crankshaft connecting rod mechanism to convert rotary motion to linear reciprocating motion, driven reciprocating plunger. (2) hydraulic end :( Figure 2) by the plunger deputy, cylinder, head, and out of the valve group, safety valves and other components. Reciprocation of the plunger rod driven, so that an inner volume of the cylinder cycle, when a suction stroke of the plunger when the valve is closed, the top of the working medium at atmospheric pressure entered into the valve cylinder; in the discharge stroke, water valve is closed, the plunger will work through the media and by the pump head discharge valve. The process is repeated periodically, thereby completing the pump suction and discharge the working medium function. 2, pressure relief valve (3) for adjusting the pump output pressure and the constant system pressure. Clockwise rotation of the adjusting nut, the pump output pressure rises, on the contrary, the output pressure is reduced. When the user needs constant output pressure at the set value simply lock and lock nut. 3, check the pressure relief valve (Figure 4) is used to automatically truncate the packing and removing the system pressure. After holding pressure test, open the relief valve hand wheel, you can dismount the system pressure. Re-boost the boost process, if the system pressure is higher than should be erroneous set value, the relief valve opens may be appropriate handwheel, after removing some of the pressure. Equipped with a pressure gauge on the valve, showed the line pressure in the boost pressure test process and packing process.