At present, the main principle of bolt pre-tightening is that ordinary (not required) bolts are usually mechanically (pure human and mechanically tightened), and torque wrenches are required to use torque wrenches or labor-saving wrenches, which have strict requirements for torque or bolt extension. Long-term bolts are pre-tightened by electric heating or hydraulic stretching according to the specific conditions (in the use of Shenyang Pump Co., Ltd., the early use tends to be electric heating, and now tends to hydraulic stretching method) . In the production of pumps, the series of high-pressure boiler feed pumps are pre-tightened by electric heating, the nuclear power pumps (including nuclear main pumps) are produced, and the subcritical and supercritical high-pressure boiler feed pumps are hydraulically stretched. Preloaded.
Since the pre-tightening of the bolt by the electric heating method requires drilling on the bolt, it is suitable for the bolt having a larger diameter, and the hydraulic stretching method requires a longer thread length, and is suitable for a pump having a large pre-tightening space. There are many pumps that do not have such conditions. For example, early single-shell boiler feed pumps and petrochemical hydro-pumps have larger bolt diameters and more compact space. Only general-purpose wrenches can be used. Today's high-pressure boiler feed pumps for generator sets (Double-shell structure) bolts, the diameter of the pump cylinder is large, the space is relatively large, and the hydraulic drawing method is relatively accurate (the domestic pump and the foreign early adopting the electric heating method, and the foreign countries now mostly adopt the hydraulic stretching method) Pre-tightening). Hydraulic stretching method for bolt pre-tightening, usually by high-pressure hydraulic manual (plunger) pump (including high-pressure oil meter and transition joint), three-way (also five-way as required), high-pressure oil hose, quick connector Bolt (dedicated) hydraulic tensioner.
The capacity of offroad winches differ from 2000lbs to 20000lbs. Normally winch line pull below 5000lbs are for UTV/ATV, winch line pull between 8000lbs and 15000 lbs are for cars like Jeeps, winches over 15000lbs are designed for trucks. Below are some 4X4 winches for sale.
There are also DC electric hydraulic winches from 10000lbs t0 20000lbs. To install such winches, hydraulic pumps are needed.
Car Winches or electrical 4x4 winches, they are commonly available with either a 12V DC or a 24 V DC motor.so confirm the winch voltage you need before buying a winch. And the voltage does not affect the winch motor housing shape, however the inside motor quality sometimes will. There`s almost no difference between the price of 12v and 24v.
Electric Recovery Winches are powered by a motor that runs off either your vehicle's battery or power steering pump. The vehicle's battery power is transferred through the winch's motor to the gear train, causing the winch drum to rotate the rope or cable in a rapid spinning motion.
When choose an electric winch, take the maximum load that you expect to winch and multiply it by 1.5, then you`ll know which one to choose.
The weight rating of these off road winches is based on the first wrap of the cable around the drum. With each layer of cable, the pull capacity actually drops, so when in doubt, go larger. Below is an example of winch performance of each layer for your reference.
Besides, if you need a fast speed winch, pls also take a look at the gear ratio your suppliers offered. As for winches in 12000lbs, the normal gear ratio is 265:1, if you prefer fast speed, you may choose 158:1, which means the actually line of pull may be smaller at the same time.
If you have any questions, please contact with us directly. Welcome you can visit our Factory. For inquiry, please send mail directly to us.
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