Category Archives: Technical Literature

Three valves in the chemical, plastics, foundry industry, is widely used in the past, mostly manual operation. With the development of science and technology, automatic control technology has been widely used in various production areas, Three air control valve is in this case was born. Three air control valve control technology can power a stretch in the production process to achieve automatic control.

Three air control valve structure as shown in Figure 1.

Figure 1 Three air control valve structure (1. Cylinder block 2. Piston 3. Rod 4. Cylinder head 5. Roller assembly 6. Screw guide sleeve 7. Protective cover 8. Stem 9. Adjustment of wire sets 10. spiral sets of shell 11. valve 12. valve port 13. spool)

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Abstract: safety valve sealing surface is too narrow and inappropriate choice of valve materials is the main reason of safety valve annular scars.

Keywords: safety valve; valve flap; opening pressure (set pressure); sealing pressure

Safety valve is widely used in boiler and pressure vessel overpressure relief device on, the performance can meet the requirements of the safe operation of boilers and pressure vessels is essential. According to the order requirements, the safety valve should be inspected regularly, at least once a year. “The steam boiler safety technology supervision order” under Article 145, for the newly installed boiler safety valve and safety valve after repair, but also to test its opening pressure (set pressure) and the sealing pressure.

China provides: steam boiler safety valve sealing test pressure to take 90% of opening pressure and reseating pressure of the lesser value. Air or other gases and water or other liquid with a safety valve sealing test pressure, when the open when the pressure is less than 0.30MPa, lower than the opening pressure 0.030MPa, when the opening pressure of 0.30 MPa greater than or equal to 90% when the opening pressure.

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Abstract: The first color penetration testing conducted after the two testing magnetic particle inspection process technology method for surface inspection of diesel engine valve, a separate use of complementary coloring inadequate testing or magnetic particle testing to ensure test quality and reliability.

Key words: diesel engine; valve; surface inspection

1. Cause valve failure and the need for surface inspection

Diesel engine valve in the service process, the downtime caused by failure, resulting in economic losses. Diesel engine valve failure are the following three reasons: First, as the valve can not be reset while the Pistons hit touched off; Second, poor body raw materials (such as surface cracks, inclusions, etc.) caused during the manufacturing process defects (such as forging cracks, stress concentration due to machining marks and microcracks formed in service); third, the body flow by heat stress and heat stress corrosion cracks generated.

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Abstract: This paper introduces a theory developed based on the jet pipe in the water industry application of new antifreeze device.

Key words: pipe; jet; frost valve

1. Introduction

In northern China, mostly in winter minimum temperature -30 ℃ ~ -20 ℃ between the individual areas of up to -40 ℃, frozen earth depth is generally between 0.5m ~ 1.5m, this winter for the rural and urban water use is very difficult. At present, the water industry, the existing antifreeze device or complex, higher prices; or drip serious, the use is not ideal. We successfully developed based on the principle of jet pipes FDJ-100-I-type jet freeze valve device to overcome the shortcomings of the antifreeze, the antifreeze has a good effect.

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The hydraulic machinery to drive in the form of ZL series loaders, most equipped with shut-off valve switch (located in the cab on the dashboard.) We are in the process of maintenance on the loader, often found that the valve had been removed; Even still, by the operator to know, do not know how to apply, useless. The main reason is the cut-off valve connected to the loader chassis switch between the gas transmission system, it is often unclear awareness. In fact, normal application of cut-off valve switch, traffic safety for the protection of the loader, extended machine life and increase economic efficiency is very important. Must correctly grasp the function of shut-off valve switch, the use of time and use.

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RZF type automatically turn off household gas pipeline valve (referred to as the automatic valve) is used to protect the liquefied petroleum gas and natural gas, pipeline gas for domestic security, a new class of patent-specific valve. Automatic valve is a rod, valve cover, rubber bowl, ring, armature film, ring magnets and other components. Gas from the inlet into the valve chamber, due to magnetic force, is normally closed outlet, manual extraction of the valve opening rod, the valve outlet is opened, gas from the outlet through the valve chamber into the combustion gas appliance. At this point, the gas pressure is greater than magnetic force, the valve is normally open, automatic valves work properly. When the air stops gas, pipeline and valve chamber gas pressure dropped to less than the critical work of automatic pressure valve, the valve automatically closes. Two air supply, you must re-extract the bar (open valve), automatic valve to return to normal work. Thus avoiding the gas without stopping off for gas appliance valves, when gas supply when the air again, making a large number of gas spills, leading to gas poisoning or fire.

Standards and technical requirements based on business, I use two 0.2 50kPa pressure gauge micro, small air compressor (with tanks), regulators, stopwatch, hoses and other test system components, see below.

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