NJS high-power hydraulic torque wrenchDetailed product description：

1、 NJS high-power hydraulic torque wrench (hydraulic torque wrench) product model and applicable bolt and nut range

Table 1 Models, Parameters, and Applicable Scope

Product Model	Maximum pressure of oil cylinder (MPa)	Oil cylinder diameter mm	Maximum working torque N.m	Hydraulic cylinder stroke sleeve angle	Applicable thread range of wrench (coarse thread)
NJS-1	sixty-three	forty	nine thousand nine hundred and fifty-four	36 °	M20-M30
NJS-2	sixty-three	forty-five	twelve thousand and six hundred	36 °	M30-M48
NJS-3	sixty-three	forty-five	fourteen thousand eight hundred and sixty-eight	34 °	M48-M56
NJS-4	sixty-three	sixty-five	forty-one thousand three hundred and ninety-one	34 °	M64-M80
NJS-5	sixty-three	sixty-five	forty-one thousand three hundred and ninety-one	30 °	M90-M100

2、 NJS high-power hydraulic torque wrench (hydraulic torque wrench) product introduction
With the continuous improvement of the technological level of China's machinery manufacturing industry, in order to ensure product quality, many equipment and facilities have adopted and will increasingly adopt high-strength bolts, and strict requirements have been put forward for the pre tightening torque of bolt fastening, especially for heavy machinery equipment that can withstand heavy loads and strong impact vibrations. In order to improve the quality and reliability of threaded connections and accurately control the pre tightening torque of high-strength bolt connections, our factory's scientific and technological personnel have comprehensively applied advanced technologies at home and abroad to successfully develop hydraulic torque wrenches, which can help you solve this problem.
Hydraulic torque wrench is an ideal tool to help you install and remove bolts and nuts, while also accurately controlling the tightening torque. It is widely used in mechanical equipment and facilities in metallurgy, power, chemical, mechanical, communication and other industries. It can install, disassemble and repair important bolt connections conveniently and quickly, and can effectively ensure the torque value you need.
3、 Structure and working principle of NJS high-power hydraulic torque wrench (hydraulic torque wrench)
The hydraulic torque wrench (see Figure 1) consists of two parts: a manual high-pressure pump and a hydraulic torque wrench with a ratchet wheel. Manipulate the handle of the manual high-pressure pump, the hydraulic cylinder generates thrust, which forms torque through the crank system, drives the nut to rotate an angle, and transmits the torque to the hexagonal socket with ratchet device for bolt connection. Pre tighten the bolt as required.
The manual high-pressure pump consists of a control handle, a high-pressure pump, a reversing valve, an oil tank, a pressure gauge, and an oil delivery pipe with a quick connector. The hydraulic wrench with a ratchet wheel is composed of a high-pressure oil port, a hydraulic cylinder, a crank, a reaction rod, a ratchet device, a sleeve, etc. The former is a power source component, and the latter is a torque actuator.

Figure 1

4、 Main features of NJS high-power hydraulic torque wrench (hydraulic torque wrench)
Hydraulic torque wrenches have the following characteristics:
(1) The pre tightening torque can be accurately and reliably controlled through the hydraulic system pressure gauge.
(2) Improve the rigidity of threaded connections and reduce the risk of bolt fatigue fracture.
(3) Ensuring the reliability of widely using high-strength bolt connections to reduce weight and save space.
(4) Widely applicable and adaptable, it can be used for pre tightening bolts and internal angle screws.
(5) Easy to operate, convenient to use, and economically safe.
5、 NJS high-power hydraulic torque wrench (hydraulic torque wrench) operation method
1. Select an inner hexagonal socket according to the size of the pre tightened nut.
2. According to the requirements for tightening or loosening the nut, combine the ratchet (use a right-hand ratchet when tightening the nut and a left-hand ratchet when loosening the nut).
3. Insert the high-pressure and low-pressure rubber hoses with quick connectors into the connection between the wrench and the directional valve (1/4 "for high pressure and 3/8" for low pressure), and after inserting them into place, rotate the outer sleeve of the quick connector by one angle to lock it.
4. The reaction rod should rely on the corresponding hexagonal support sleeve or other place that can withstand the reaction force.
5. The size of the wrench connecting rod angle should be controlled within the angle range calibrated by the reaction rod.
6. When pressurizing, the air release valve should be rotated to the left once, opened, and closed after all the air has been released.
7. When manually pumping, rotate the reversing valve handle according to the extension and contraction of the hydraulic cylinder piston rod. When the handle is in the left position, the piston rod extends, and vice versa. When in the middle position, the pressure is zero.
8. When applying pressure, the torque value can be obtained by observing the reading on the pressure gauge (MPa). The pressure value (MPa) at the required torque value (N.m) should be calculated in advance according to the formula given in Table 2.
9. After pre tightening, place the reversing valve handle in the middle position to return the pressure to zero.
10. When removing high and low pressure rubber hoses with quick couplings, the outer sleeve of the quick coupling should be rotated by an angle first, so that its notch aligns with the limit pin and pushed forward, and then the coupling can be pulled out.
Six NJS high-power hydraulic torque wrench (hydraulic torque wrench) precautions
1. The connecting hose should be in a free state and should not be coiled into circles with a diameter less than 500mm.
2. Lubricating grease should be applied to the connecting pins and moving parts of the hydraulic wrench to reduce torque loss caused by friction.
3. The hydraulic system should not be manually connected during operation.
4. After removing the quick connector, the exposed part of the connector must be covered with a plastic cover.
5. The working oil is ordinary hydraulic oil, with the grade of YA-N32G or YA-N45G. (Equivalent to 20 # engine oil). The working oil in the system must be replaced and the filter cleaned every year.
7、 Application of hydraulic torque wrench
1. Select the wrench model you need based on the size range of the threaded connection, and do not use a small wrench to tighten large-sized bolts.
2. The cylinder pressure should not exceed the maximum oil pressure of 63MPa to avoid damaging the hydraulic system.
3. Calculate the required pressure (MPa) or torque (N.m) according to Table 2 and the corresponding formulas for different types of wrenches.
Example 1: Use NJS-I wrench to tighten M30 bolt with a pre tightening torque of 1004N. m. Refer to Table 2 and use the formula P=M1/158=1004/158 ≈ 6.4MPa. When the pressure gauge pointer reaches 6.4MPa, its torque is 1004N. m.
Example 2: Use NJS-II wrench to tighten M42 bolts with a pre tightening torque of 2806N. m. Refer to Table 2 and use the formula P=M2/200=2806/200 ≈ 14MPa. When the pressure gauge pointer reaches 14MPa, its torque is 2806N. m.
Example 3: Use NJS-III wrench to tighten M64 bolt with a pre tightening torque of 10147N. m. Refer to Table 2 and use the formula P=M3/236=10147/236 ≈ 43MPa. When the pressure gauge pointer reaches 43MPa, its torque is 10147N. m.
Example 4: Use NJS-IV wrench to tighten M80 bolts, with a pre tightening torque of 19626N. m. Refer to Table 2 and use the formula P=M4/657=19626/657 ≈ 29.9MPa. When the pressure gauge pointer reaches 29.9MPa, its torque is 19626N. m.
Example 5: Use NJS-V wrench to tighten M100 bolt with a pre tightening torque of 39960N. m. Refer to Table 2 and use the formula P=M4/657=39960/657 ≈ 60.8MPa. When the pressure gauge pointer reaches 60.8MPa, its torque is 39960N. m.
On the contrary, if the pressure (MPa) is known, the corresponding torque (N.m) can also be calculated according to the corresponding formula given in Table 2

Table 2 Hydraulic Torque Wrench Cylinder and Corresponding Torque, as well as Pressure and Torque Calculation Formulas

Pressure gauge reading MPa	Torque N.m
	NJS-I type, when calculating torque with known pressure, use M1=158P. When calculating pressure with known torque, use P=M1/158	When calculating torque with known pressure for NJS-II type, use M2=200P. When calculating pressure with known torque, use P=M2/200	NJS-III type, when calculating torque with known pressure, use M3=236P. When calculating pressure with known torque, use P=M3/236	NJS-IV (V) type, when calculating torque with known pressure, use M4=657P. When calculating pressure with known torque, use P=M4/657
one	one hundred and fifty-eight	two hundred	two hundred and thirty-six	six hundred and fifty-seven
two	three hundred and sixteen	four hundred	four hundred and seventy-two	one thousand three hundred and fourteen
three	four hundred and seventy-four	six hundred	seven hundred and eight	one thousand nine hundred and seventy-one
four	six hundred and thirty-two	eight hundred	nine hundred and forty-four	two thousand six hundred and twenty-eight
five	seven hundred and ninety	one thousand	one thousand one hundred and eighty	three thousand two hundred and eighty-five
six	nine hundred and forty-eight	one thousand and two hundred	one thousand four hundred and sixteen	three thousand nine hundred and forty-two
seven	one thousand one hundred and six	one thousand and four hundred	one thousand six hundred and fifty-two	four thousand five hundred and ninety-nine
eight	one thousand two hundred and sixty-four	one thousand and six hundred	one thousand eight hundred and eighty-eight	five thousand two hundred and fifty-six
nine	one thousand four hundred and twenty-two	one thousand and eight hundred	two thousand one hundred and twenty-four	five thousand nine hundred and thirteen
ten	one thousand five hundred and eighty	two thousand	two thousand three hundred and sixty	six thousand five hundred and seventy
twenty	three thousand one hundred and sixty	four thousand	four thousand seven hundred and twenty	thirteen thousand one hundred and forty
thirty	four thousand seven hundred and forty	six thousand	seven thousand and eighty	nineteen thousand seven hundred and ten
forty	six thousand three hundred and twenty	eight thousand	nine thousand four hundred and forty	twenty-six thousand two hundred and eighty
fifty	seven thousand and nine hundred	ten thousand	eleven thousand and eight hundred	thirty-two thousand eight hundred and fifty
sixty	nine thousand four hundred and eighty	twelve thousand	fourteen thousand one hundred and sixty	thirty-nine thousand four hundred and twenty
63max	9954max	12600 max	14868 max	41391max