Control valve test methods and main performance: 1.1 pneumatic control valve main performance and test: Pneumatic control valve performance indicators are: basic error, backlash, dead zone, always point deviation, rated stroke deviation, leakage, sealing, resistance Pressure intensity, appearance, rated flow coefficient, the inherent flow characteristics, resistance to vibration performance, action life, count 13, the first 9 items for the factory inspection items. Due to the transportation of control valve, the adjustment of the working spring range and other factors, it is often necessary to adjust and inspect the following performance before installation: 1) Basic error Input the specified input signal steadily in the increasing and decreasing direction to the actuator air chamber Positioner), measuring the stroke value corresponding to each point to calculate the actual "signal - stroke" relationship between the theoretical relationship and the point of error. The maximum value is the basic error. The test point shall include at least 5 points of signal range 0, 25%, 50%, 75%, 100%. Measuring instrument basic error limit is less than the test valve basic error limit of 1/4. 2) The hysteresis test procedure is the same as described in point 1) above. In the same input signal measured positive and negative travel of the maximum difference is the backlash. 3) always point deviation method with the first) point. The basic error at the upper limit (starting point) of the signal is the starting point deviation; the basic error at the lower limit (end point) of the signal is the ending point deviation. 4) Rated Stroke Deviation Add the rated input signal to the air actuator (or positioner) of the pneumatic actuator so that the valve stem can be fully extended. The difference between the actual stroke and the rated stroke and the rated stroke are the rated stroke deviations. The actual travel must be greater than the rated travel. 5) Leakage test medium is 10 ~ 50 ℃ clean gas (air and nitrogen) or liquid (water or kerosene); Test pressure A program: When the valve allowable pressure is greater than 350KPa, the test pressure is done by 350KPa, When the pressure is less than 350KPa, it is allowed to do the pressure; B, the test procedure is done according to the maximum working pressure of the valve. Test signal pressure should ensure that the valve is closed. A pilot program, the gas valve actuator pressure signal is zero; gas valve actuator signal pressure for the input signal plus the upper limit plus 20KPa; two-valve actuator signal pressure should be the design value. In the B test procedure, the actuator signal pressure shall be the design specification. The test medium should be fed into the valve as required. The outlet of the valve can be directly connected to the atmosphere or the low pressure head loss measuring device connected to the outlet of the atmosphere, and the leakage can be measured only after the valve and the downstream connecting pipe are completely filled with the medium. 1.2 The main performance of electric control valve and test: electric control valve main performance indicators are: basic error, backlash, dead zone, the rated stroke deviation, leakage, sealing, compressive strength, appearance, rated flow coefficient, the inherent flow characteristics, Vibration resistance, temperature, long-term reliability, explosion-proof, damping characteristics, changes in supply voltage, environmental temperature changes, insulation resistance, dielectric strength. The first 10 indicators of the requirements and test methods are the same or similar with the pneumatic valve, in which the basic error, backlash, dead zone, leakage, sealing, appearance, damping characteristics, power supply voltage changes, the insulation resistance of the factory test items, 3 performance requirements and test methods are as follows: 1) Damping characteristics Damping characteristics of the electric control valve, in both positive and negative direction of the provisions of the stem does not exceed 3 "half-cycle" swing. The test method is to input the input signal range value of 20%, 50%, 80% of the signal to observe the valve stem in the positive and reverse stroke corresponding position "half-cycle" number of oscillations. 2) Changes in power supply voltage When the supply voltage of the electric regulating valve changes within the range of 220 + 20-30V, the displacement of the stem should not exceed 1.5% of the full stroke. The test method is to measure the corresponding stem stroke value of the signal of 20% of the signal range value at the input voltage of 220V and adjust the power supply voltage to 190V and 240V to measure the corresponding stem stroke change value . Then turn on the signal range value of 50%, 80% of the signal, measure the valve stem travel changes. 3) Insulation resistance When the ambient temperature is 10 ~ 35 ℃, the relative humidity does not exceed 85%, the insulation resistance of the electric control valve should meet the following requirements: the input terminal to the chassis is not less than 20MΩ; each input terminal to the power supply terminal is not less than 50MΩ; power terminals on the chassis is not less than 50MΩ. Test method is the use of 500 megohmmeter test. More keyword search: Regulating valve
Marine Electro-hydraulic Windlass
The windlass is installed on the main deck of the ship's bow, which is used for the ship to lift the anchor and drop the mooring cable.
Windlass can be divided into manual, electric, hydraulic, pneumatic, etc. according to the driving form.
The windlass can be divided into several specifications such as φ12--φ120mm according to the diameter of the anchor chain.
Windlass can be divided into single-sided and double-sided according to the distribution of drums.
The windlass is mainly composed of base, bracket, chain wheel, brake, chain wheel, gearbox, electric control system (except manual windlass), etc. Electric windlasses have electric motors, and hydraulic windlasses have hydraulic pump stations.
The main technical indicators of the windlass include the diameter of the anchor chain, the nominal speed of the anchor, the rated load, the supporting load, several levels of speed change, electrical system, etc. The installation of the windlass on the ship should ensure that the wrap angle between the anchor chain and the sprocket is 117-120°.
Electric windlass
The electric motor directly drives the windlass, and the drive shaft is driven by the gear box to work, and the structure is simple; it is generally suitable for windlasses with an anchor chain diameter of 16mm-93mm.
hydraulic windlass
It is suitable for windlass with anchor chain diameter of 16mm-120mm. Hydraulic windlasses are also called electro-hydraulic windlasses. It drives the oil pump with a motor, drives the motor with high-pressure oil, and then drives the transmission gear through a reducer (or no reducer). To make the windlass run, its structure is relatively compact and its volume is small. Now there has been an automatic hydraulic windlass, which is equipped with an anchor chain length sensor. When the anchor chain needs to be thrown out, the windlass will automatically stop; , can automatically decelerate; the anchor will automatically stop when it enters the anchor chain drum and is properly received.
Marine Electro-Hydraulic Windlass,Windlass Anchor,Electric Windlass,Manual Windlass
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