hydraulic jack safety valve manufacturer

The present invention relates to an improved safety valve structure for a hydraulic jack, particularly to an improved structure of the safety valve inside a pump base of the jack so that high pressure hydraulic fluid can smoothly and accurately flow through the valve and return to a reservoir.

A one-way valve is usually provided between the reservoir and the pump base of a hydraulic jack. The one-way valve is used to control hydraulic fluid flowing from the reservoir into a pump. The valve also cooperates with the up-and-down movement of a lever on the jack so that the hydraulic fluid can be forced into a pressure tank for pushing a piston upward. When the jack is overloaded and the hydraulic pressure inside the jack has reached a predetermined limit, a safety device is needed to discharge the hydraulic fluid back into the reservoir. A conventional safety device uses a steel ball and a safety spring secured by an adjustment screw. The adjustment screw is used to adjust the pressure of the safety spring which presses against the steel ball. When the pressure inside the pressure tank is higher than the pressure of the safety spring set by the adjustment screw, the steel ball will automatically be pushed rearwardly against the force of the safety spring so that the safety spring is compressed, thus enabling the steel ball to disengage from a valve seat. Thus, the path previously closed by the steel ball is opened and the hydraulic fluid can return to the reservoir, thereby lowering the pressure within the pressure tank and preventing the pressure tank from cracking or exploding. However, the operation of the above arrangement is not reliable, since it is easy for the steel ball to deviate from an opening path of movement. Therefore, discharge of the hydraulic fluid is unstable and results in rough operation.

The main object according to the present invention is to provide an improved safety valve structure for hydraulic jacks. The structure is provided with a push pin, a safety spring and an adjustment screw. The end of the push pin is placed inside the axial hole of the adjustment screw. The adjustment screw is used to adjust the compression of the safety spring so as to control the pushing force of the push pin. By such configuration, the push pin can be used to seal the opening as well as to guide the hydraulic flow when the push pin is retracted. Thus, it provides for smooth operation when the hydraulic oil is discharging.

As shown in FIGS. 2 and 3, a safety valve according to the present invention is provided inside a valve body of a one-way valve 1 of a hydraulic jack. The one-way valve 1 is provided inside a pump base 6 of the hydraulic jack and a pump 7 is provided on the pump base 6. The one-way valve 1 includes a cylindrical valve body. The cylindrical valve body has an annular recess or slot 11 formed in an exterior wall thereof.

An L-shaped oil inlet channel 12 defines an oil inlet port 121 at slot 11 and a port opening at the top surface of the one-way valve 1. A filtering screen is provided in the inlet channel 12 at oil inlet port 121. The L-shaped oil inlet channel 12 is a two-step channel having a larger diameter portion at the top and a smaller diameter portion at the bottom. A steel ball 123 and a compressed spring 124 are provided in the larger portion of the channel. The compressed spring 124 engages a projection defining the upper opening so as to be secured without disengaging. Also, the steel ball 123 seals the upper neck opening of the smaller diameter portion of the channel. In addition, the top surface of the one-way valve 1 is provided with an oil discharge port or hole 13, which is a two-step passage or hole having a larger diameter bottom portion and a smaller diameter top portion. The larger diameter portion of the channel is provided with a steel ball 131 and a compressed spring 132. The compressed spring 132 is secured in place by engaging an inwardly extending projection defining a bottom opening. Also, steel ball 131 seals the bottom opening of the smaller diameter portion. In addition, the wall of the annular slot 11 of the one-way valve 1 is provided with a safety oil discharge port or hole 14, which communicates with the smaller channel portion of the oil discharge port or hole 13.

As shown in FIGS. 2 and 3, the safety oil discharge hole 14 is a two-step passage or hole having a smaller diameter portion 141 which communicates with the smaller portion of the oil discharge hole 13. A rearward section of a larger diameter portion 142 is provided with inner screw threads. A push pin 2, as well as a safety spring 3, are placed in the larger portion 142 and an adjustment screw 4 is used to secure the pin 2 and spring 3 in place. A forward portion of push pin 2 is a cone-shaped body 21 and a rearward portion is a two-step rod or post 22, in which a large-diameter portion is inserted into the safety spring 3 in the axial direction, the small-diameter portion is inserted into an axial hole 41 of the adjustment screw 4. In this configuration, the resilient force of the safety spring 3 is applied so that the cone-shaped body 21 of the push pin 2 seals an end of the smaller portion 141 of the safety oil discharge passage 14. An end of safety spring 3 is engaged by adjustment screw 4, which is screwed and secured inside the larger portion 142 of the safety oil discharge hole 14. Also, the force of the safety spring 3 and thus the sealing force of push pin 2, can be adjusted by adjusting the adjustment screw 4 in the larger portion 142 of the safety oil discharge hole 14. In addition, the axial hole 41, provided on top of the adjustment screw 4, is used for discharge of the hydraulic fluid.

By use of the push pin 2, provided in the safety oil discharge hole 14 to cooperate with the safety spring 3 and the adjustment screw 4, the pump 7 can be removed and the one-way valve 1 can be taken out. By turning the adjustment screw 4, the compression ratio of the safety spring 3 can be set and the force of the push pin 2 acting against the smaller portion 141 of the safety oil discharge hole 14 can also be adjusted. Thus, the force from the safety spring 3 pushing against the push pin 2 can be set as the critical value of the hydraulic safety load coefficient. In other words, safety spring 3 and push pin 2 limit the pressure of the hydraulic jack. During operation, when the safety load value of the hydraulic fluid within the jack reaches the limit (i.e., when the load exceeds the setting of the push pin 2), the push pin 2 inside the safety oil discharge hole 14 is displaced backwardly by the hydraulic pressure and compresses the safety spring 3. At this time, the push pin 2 disengages from the smaller portion 141 of the safety oil discharge hole 14 and therefore, the hydraulic circuit is a closed circuit. This means that the hydraulic oil can circulate through the safety oil discharge hole 14, the axial hole 41 of the adjustment screw 4, the annular slot 11 of one-way valve 1 and return into the oil storage tank, allowing the pressure inside the jack to be depressurized. When the pressure inside the hydraulic jack decreases to within the safety load limit, the force from the safety spring becomes higher than the internal hydraulic pressure of the hydraulic jack, and therefore, the safety spring 3 automatically biases the push pin 2 forward so as to seal off the small portion 141 of the safety oil discharge hole 14. By this setup, the safety of the hydraulic jack can be assured and an explosion can be prevented. In addition, the push pin 2 is a linear fluid guide inside the safety oil discharge hole 14. When the latter is discharging, turbulence is prevented and a smooth operation can be assured. It is indeed a compact, practical and modern design.

By use of the above configuration, the flow of the hydraulic oil is described as follows: when the lever 5 is pulled up, the hydraulic oil inside the reservoir is sucked through an inlet 61 inside of the pump base 6. The oil follows the L-shaped oil inlet channel 12 and flows into pump 7. When lever 5 is pressed downwardly, hydraulic oil inside pump 7 is forced out through oil discharge hole 13 of the one-way valve. The oil follows an outlet path 62 of pump base 6 back into the pressure tank of the hydraulic jack so as to drive a piston up for lifting (now shown in Figure). However, if the lifting load of the jack exceeds the maximum design load and a user continues to operate lever 5 to force hydraulic oil into the pressure tank; the pressure could cause the pressure tank to crack or explode. Therefore, when the hydraulic pressure exceeds the safety limit, the improved safety valve structure, according to the present invention, allows the hydraulic pressure to push the push pin 2 inside the safety oil discharge hole 14 backwardly so that the hydraulic oil can follow the path through the annular slot 11 and through the inlet path 61 of the pump base and then return into the oil reservoir. Thus, the pressure inside the pressure tank can be controlled. In addition, the structure of push pin 2 provides a linear fluid guide so that the oil flow is smooth and accurate.

... assemble/disassemble Handle supplied with a small hook to get from under the vehicleIdeal to be used in combination with the CP jack standsThis product is not marketed yet in North America and Australia.

... lowered roll can be brought up easily with the pressure relief valve. You can easily adjust the equipment with the handle on the jack. There is a powerful piece of equipment that will help you to lift the loads.

... hydraulic jacks is very simple. Jacks are supplied ready for use, i.e. including hydraulic oil, operating lever and, where applicable, carrying handle and lifting claw.

... multitude of modifications on our jacks to suit any pit! Please complete a Pit Survey form for an accurate quote. We also offer Distributor rates if you wish to become a re-seller please contact us for more information.

ECO-Jack® heavy duty hydraulic jacks are available in five different series with payloads up to 25 tons. The adjustability of the lifting claw on all ECO-Jack® is patented ...

ECO-Jack® heavy duty hydraulic jacks are available in five different series with payloads up to 25 tons. The adjustability of the lifting claw on all ECO-Jack® is patented ...

The ECO- Jack S Series is composed of hydraulic machinery toe jacks from HTS Hydraulische Transportsysteme GmbH. They can lift heavy loads like tools, machines, and dies that follows ...

The hydraulic jack allows you to unwind the cable ( pay-off ) from drums with safety. You can use it in combination of a winding a machine or using it for cable installation.

The hydraulic jack allows you to unwind the cable ( pay-off ) from drums with safety. You can use it in combination of a winding a machine or using it for cable installation.

The hydraulic jack allows you to unwind the cable ( pay-off ) from drums with safety. You can use it in combination of a winding a machine or using it for cable installation.

Complete range of suspended or floor pit jacks. Ergonomic and modern design with work-height control-panel. The 2 individually controlled rams offer safe and balanced lifting.

For lifting of machines and other heavy loads. Easy lifting with lifting claw and end plate by means of installed hydraulic hand pump. Precise lowering via lowering valve, overload valve. Pump lever detachable. Swivelling ...

Select from a variety of wholesale hydraulic bottle jack relief valve for the appropriate type of equipment that you need. There are several popular hyd bottle relief valve on sale at great prices. Some examples include the solenoid valve, water pressure regulator, actuator valve, globe valve, and sprinkler valve. These instruments can be used to control the flow of substances in the liquid and gaseous states. Whether you are a scientist, plumber, or store supplier, you will likely be able to find the right tools for the job.

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There are many uses of valves - mainly controlling the flow of fluids and pressure. Some examples include regulating water for irrigation, industrial uses for controlling processes, and residential piping systems. Magnetic valves like those using the solenoid, are often used in a range of industrial processes. Whereas backflow preventers are often used in residential and commercial buildings to ensure the safety and hygiene of the water supplies. Whether you are designing a regulation system for irrigation or merely looking for a new replacement, you will be able to find whatever type of hydraulic bottle jack relief valve that you need. Our products vary from check valves to pressure reducing valves, ball valves, butterfly valves, thermostatic mixing valves, and a lot more.

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A hydraulic shop press is a type of machine press that uses a cylinder in order to create a compressive force. The force of the shop press can be used for a variety of jobs such as clinching, moulding, forging and metalworking; it also has the ability to create a variety of intricate shapes for mo

Hydraulic Jack with Safety Valve Bottari, 5T manufactured so that it can lift a capacity of 5t. with height from 195 to 380 mm. Contains the safety valve.

Manufacturer of standard & custom hydraulic & lift jacks used for aircraft, automotive & industrial applications. Types include scissors lift tables, low profile tables, tilt tables, 3 point entry lift tables, hydraulic scissors lift tables, double scissors lift tables, maintenance lift tables, dock scissors lift tables & post lift tables. Optional features include hydraulic motors from 2 hp to 10 hp, air motors, wash down motors, self propelled drives, rubber bumpers, limit & proximity switches, double acting power systems for conveyor & material transfer applications & rotating table tops. Services include engineering, automation & leasing.

A hydraulic jack serves one fundamental goal: the lifting of heavy loads. Jacks are designed to provide force multiplication to enable a worker to amplify their strength through the jack"s hydraulics or mechanics to accomplish this goal.

There are two main types of jacks commonly in use; one type uses hydraulic pressure for lifting (hydraulic jacks), while the other uses a screw thread to achieve lift (mechanical jacks). Of the two, hydraulic jacks usually provide higher lift capacity and are more reliable.

Hydraulic jacks are available in two varieties: floor jacks and bottle jacks. Floor jacks have a horizontal shaft that pushes on a crank. The crank connects to a lifting pad that rises vertically. These jacks are capable of lifting several tons.

Bottle jacks have been around longer, and their name derives from their resemblance to an old-fashioned milk bottle. Bottle jacks have a vertical shaft that raises a platform called a bearing pad. They can lift up to several hundred tons, depending on the specific capabilities of the model being used. However, these jacks typically cannot lift the load to the same height as with a floor jack.

Both types of jacks operate under the same basic principle: In a closed container, the pressure is the same in all directions. In the case of a hydraulic jack, this container is a cylinder, and it holds incompressible hydraulic fluid. Hydraulic fluid is forced into the cylinder through a check valve that prevents the fluid"s backflow. The check valve keeps the cylinder pressurized so the load does not drop. As pressure builds in the cylinder, the force pushes upward on the plate of the jack and lifts the load resting on it. The weight of the load lowers the plate when the check valve is released, allowing the hydraulic fluid a path to exit.

There are some issues that are common to all types of hydraulic jacks which can impact their operation and safety. At some point, users will likely encounter leaks, rams that won’t lift, safety valves that get tripped, damage to the frames, and jack handles that kick back. While many hydraulic jack repairs are easy to accomplish, others might require the assistance of a professional.

Leaks, in particular, are extremely common, and result from a failed or dislodged seal or O-ring. Repair involves draining the hydraulic fluid, disassembling the jack, and inspecting the seals. Be sure to look carefully for cuts, tears, seals that are out of place, degradation, scratches, and so on. These issues are an indication that the seals or O-rings need to be replaced.

Repairing leaking seals can be a significant undertaking, especially for those not experienced in jack repair. Novices might want to leave this type of issue to a professional with the requisite experience. Also, if the leaked fluid is cloudy or foamy, that indicates the presence of water or air in the hydraulic system and could mean that the hydraulic fluid needs to be replaced and the potential source of the intrusion investigated.

Jacks may also be overloaded, causing the safety valve to trip. The purpose of this safety feature is to prevent the jack from being loaded beyond its rated operating pressure, typically measured in pounds- force per square inch (psi). A jack will not behave the same way after the safety valve has been tripped. The ideal way to address this issue will vary by manufacturer, so always consult the service manual when this occurs. Professional service is recommended in these instances to restore safe operation of the jack.

In other cases, rams may stop lifting, which is usually the result of insufficient hydraulic fluid in the reservoir. Luckily, this is a repair that even beginners can handle. When there isn’t enough hydraulic fluid present, air may become trapped inside of the system. The solution here is to add the appropriate amount of hydraulic fluid, then turn the jack to its release position. Next, pump a few times to purge out the trapped air. Then, refill the reservoir and place the seal cap back on. Be careful to avoid introducing contamination (such as dirt and dust) to the hydraulic system while adding fluid, and never mix two different types of fluid.

Hydraulic jacks are powerful devices for lifting, but like any other mechanical or hydraulic system, they will inevitably require maintenance and occasional repairs. While someone with fundamental mechanical skills may accomplish some repairs, others are best handled by a hydraulic professional. Be sure to consider the options carefully before deciding on a course of action.

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In this article, you will learn about STE hydraulic jacks’ different aspects, such as how to use them, their prices, lifespan, quality levels, max loading capacities, max heights, and a lot more.

If possible, park the vehicle on solid ground, such as concrete, e.t.c. Plus, it is necessary to park a car in an even place to avoid Hydraulic jack misbalancing. If the ground is soft or uneven, use some hard and even plate to place under a car jack during lifting to avoid any accident.

When parked, check the handbrake is on. Also, check the wheels which are on the opposite side from the hydraulic jack, such as chock the front wheels if the hydraulic jack is lifting the back wheels, e.t.c. Handbraking and choking of wheels are done to avoid rolling of car.

Now, get the Hydraulic Jack out of its storing place and check for max load capacity, and if ok, inspect for signs of damage, especially oil leakage. After inspection, ensure that the release valve is closed tightly by turning it clockwise. Also, wipe any dust off the saddle ( the upside of the jack which attaches with the car ) to guarantee non-slippery, firm attachment with the vehicle.

First, insert the handle down in the attachment point ( which is close to the barrel ). Now give the Hydraulic jack a few pumps by moving the handle up and down slowly. When the cylinder is lifted, open the release value and lower it.

If you just want to change the car tire, then change it and lower the cylinder by directly jumping to step ( e ). But if you’re going to work underneath the car, then Hydraulic jacks alone are not recommended, and it is best to use Jack stands for maintaining a long period of lifting.

Secure them in place ( either by a pin or their built-in mechanism ). If your jack stands have an additional safety pin, also use it for extra safety.

When done working, lift the vehicle again with Hydraulic Jack by following the above guidelines, but a little higher than jack stands ( about 1 inch or 2.5 cm ). and when a load is shifted on hydraulic jacks, slide the jack stands straight and slowly from the side. Do not get under the vehicle when jack stands are being removed. Also, never lower the height of the jack stand until it is out from under the car.

Finally, for lowering the vehicle on the ground, open the release value by slowly turning it anti-clockwise with the notched side of the handle. All the fluid will be lowered immediately, moving the hydraulic jack cylinder and with it the car down.

Similarly, Scissors Jacks are also easy to use. Follow the same above steps as for Hydraulic jacks. The only difference is a Scissor Jack is lifted by putting the handle into the loop and turning it clockwise. For lowering, simply turn the handle anti-clockwise, and the scissor jack will be down. Unlike Hydraulic Jacks, there is no release valve, cylinders e.t.c in the Scissor Jacks, so operating a Scissor Jack is more work-demanding than working with a Hydraulic Jack.

In Electric Jacks, an automated system lifts and lowers the jack with just the press of buttons. There is neither a need for pumping with a handle nor closing and

Do not leave a car on hydraulic jacks for a long period because even a small leakage may cause the jack to fail and cause an accident. But you can leave the car on jack stands for weeks.

If you are going to work underneath the vehicle, always place the jack stands and lower hydraulic jacks slowly. Before lowering the hydraulic jack completely, ensure that jack stands are steady and lift all the load perfectly.

The lifespan of a hydraulic jack greatly depends on its usage. For example, a hydraulic jack that is used rarely on a personal level can last for decades, while a hydraulic jack that is used daily many times on a commercial level will last a few years.

STE produces its Hydraulic Jacks in many 3 quality levels. The starting quality is basic, which has the least price but a shorter lifespan. In contrast, the highest premium quality Hydraulic Jacks are a little costlier but are very durable and can last for decades.

So, it is very necessary to lubricate the Hydraulic Jack various parts with all-purpose grease frequently. You can see the guidelines below to learn which parts of the Hydraulic Jack to lubricate;Springs

So, it is very necessary to clean the hydraulic jack of any debris, moisture, e.t.c, as soon as possible with a dry cloth or with a cloth soaked in a mild soap solution.

New Hydraulic Jacks do not need refilling for years unless there is a leakage. While when Hydraulic Jacks get old after years of use, the fluid in them also expires and refilling the fluid returns the working to the best condition.

If the fluid level is down, but the jack is like new, then only fill the oil but if the jack is very old, then drain the oil and refill it with a new one.

So, after seeing these indications, fill the oil in the Hydraulic Jack by following the steps;Open the release valve by turning it clockwise or pressing it or any other way depending on its design. This will lower the jack. Keep the release valve open during the whole operation.

Locate the filler plug. On bottle jacks, it is usually on the side of the main cylinder, while on trolley jacks, it is mostly underneath a plate on the handle side, and for other shape jacks, see the manual guide to find filler plug.

If a filler plug has a cover on it, remove it until the plug is visible. Depending on the design, the cover can be removed entirely or partly. For example, in trolley jacks, if needed, remove the cover plate ( fully or partially) to make the filler plug accessible.

If it is a hydraulic bottle jack, place it in an upright position, and for trolley jacks, place them straight on the ground and so on. Always place jacks on level ground during filling to estimate oil levels precisely.

If your jack has a cover, do not place it back on because, during the bleeding process, a filler plug is needed to open for releasing air out of the jack.

Sometimes the air in the jack blocks its normal functioning, such as the jack will not rise to its max height or will not work smoothly, or will not work at all, and so on. So, in these conditions, it is important to get the unnecessary air out of the jack, which is also known as Bleeding of the Hydraulic Jack.

Finally, raise the hydraulic jack for checking. If it rises to max height as well as does not show any jerky motion, then it is working fine. Otherwise, repeat the process a few times until it starts operating correctly.

The above process should work for almost all kinds of Jacks. For Hydraulic Bottle Jacks, there is a special, more advanced bleeding process, which you can see below;Raise the jack rim halfway

Standard Quality Jacks include few features and are the cheapest, while Ultra-Premium Quality Jacks have a lot of features and are the highest in price. Premium quality jacks lie in between standard and ultra-premium ones, both in price and feature aspects.

Scissors jacks, due to their simple components, are the cheapest, while Hydraulic Electric Jacks, due to their automatic motor function, are the most costly of all. All other kinds of jacks lie in between these two.

The price of any kind of a jack also mainly depends on its lifting capacity. For example, a 2-ton lifting capacity jack will be much less expensive than a 50-ton lifting capacity jack.

STE Ultra-Premium Jacks also include Welded bottle Jacks, and these jacks are very durable because the various components are welded, which lowers the chances of leakage. The only downside of being welded is that neither you can not open it nor adjust, but this feature also allows for longer life. Our Welded bottle jacks also have additional features, such as a zinc-plated handle, electroless nickel-plated rams, e.t.c, for more durability than normal bottle jacks. And above all, the price of Welded bottle jacks is only a bit higher than normal quality bottle jacks.

Jack Stands are used when you want to work under the vehicle. You may be thinking, why do you need jack stands when you have hydraulic jacks? The answer is simple. Hydraulic jacks are suitable for lifting the loads, while Jack stands are suitable for holding the loads. You can place a vehicle on jack stands for days and work under it without any worry but never get under a car, not even for a second when it is on hydraulic jacks alone. Safety pin feature is also available in Jack Stands, which provide extra security.

Scissors jacks are the simplest forms of jacks. These are fully mechanical and need almost no maintenance. Due to scissor jacks’ small size and lightweight, these are mostly used in vehicles. These are also the cheapest in the price of all jacks. But the only downside of scissor jacks is a large amount of force is needed to operate them.

Hydraulic Bottle Jacks are the most compact and easy-to-use. Their prices are lower, but load lifting capacities are higher than all other kinds of hydraulic jacks. Hydraulic Bottle Jacks have applications in many areas, such as in cars, garages, construction, and much more.

Hydraulic Trolley jacks, as the name describes, are jacks with wheels for easy moving. These are very heavy-duty Hydraulic jacks and are mostly used for commercial purposes such as in garages, workshops, e.t.c.

We at STE give a 6 to 10 digit HS code to all of our Hydraulic Jacks. The exact amount of customs duties on your shipment can be found out by giving HS code(s) to your country’s customs department.

According to ASME, in this test, all the old and new custom designs of jacks shall be tested. For passing, all jacks must meet the stated specifications without any functional or operational damage during the operation.

According to ASME 2009/2014, this loaded operational test includes a multiple series of subtests that will be done in the next headings, ( c ), ( d ), ( e ), ( f ), with a deadweight not less than the rated capacity of the jacks.

This test is performed with a loaded jack in a fully extended position. First, the jack is tilted to its greatest angle in all directions. Afterward, the jack is moved forward and backward at least 1 foot ( 305 mm ) without the wheels or casters lifting from the ground. For passing, the load shall remain on the jack after the experiment.

According to ASME 2009/2014 standards, lower the jack to its minimum height with a load on it, and move it across a 0.5 inches ( 12.7 mm ) high, 15-degree-slope rise in the floor at a speed of 1.5 ft/sec ~ 2.0 ft /sec ( 457 mm / sec ~ 610 mm / sec ). At the end of a slope, there should be a fall of 0.5 inches. The approach should be such that only one wheel or caster at a time touches the slope ( during rising) and the ground ( on the fall ). For passing, the jack must stand the test without the loss of load.

According to ASME, in this test, the jack is fully extended with a load on it, and it should neither lower more than 0.125 inches ( 3.18 mm ) in the 1st minute nor more than overall 0.1875 inches ( 4.76 mm ) in 10 minutes.

In this test, the jack is fully extended with a load on it, and the release valve is open, and the descent rate is calculated. For passing this test, the descent rate should not be more than 1 inch per second.

In this test, the load is applied to the jack, and the jack is lifted to its maximum height. For passing this test, the jack should lift and sustain the load through the lifting range. Also, any internal load-limiting device should be deactivated during this process.

As we manufacture hydraulic jacks from scratch and in a very big quantity ( about 1,500,000/- Hydraulic Jacks per month ), you can expect the cheapest prices from us.

After making, we test all jacks very carefully for any kind of faults, especially leakages. When passed we packed and shipped them. During normal conditions, you will get the cargo in about 30 days (excluding manufacturing time ).