[Translate to Polish / Polnisch:] Flow or throttle valves such as throttle check valves are important components in hydraulics. This uses the flow energy of liquids or gases for hydraulic or pneumatic applications. In this way, easily controllable linear or rotary movements can be generated.

Hydraulic systems tend to develop large forces at low speeds - for example in heavy-duty vehicles.

In terms of application possibilities, performance or price-performance ratio, both systems are unrivaled - even though a serious hydraulic alternative is emerging in the form of electromechanical actuators. However, entire small components are always decisive for the optimal, smooth functioning of even the largest hydraulic systems. These are flow control valves, such as our throttle check valves.

What are flow control valves?

Most throttle or flow control valves are single or one-piece valves. They create a pressure differential with varying flow resistances that affect the volumetric flow of a fluid. Throttle check valves, on the other hand, consist of two functions: Throttle and check valve. As with our modular throttle check valve VS01-04/M, the valves are mainly housed in a protective casing.

However, ARGO-HYTOS also manufactures throttle check valves as an optional addition to needle valves without a housing. The basic function of flow control valves always remains the same:

• The valves allow fluids to flow through throttled in one direction and unthrottled in the other. 
• A throttle, as in a normal throttle valve, reduces the line cross-section in the process.
• The throttle can create a constant restriction or be installed as an adjustable throttle.

If fluids now flow through the throttle check valves, they react in two ways:

• If a fluid flows in the desired direction, the check valve opens and unrestricted flow occurs
• If a required backflow of fluid occurs in the system, the check valve closes. •
• Fluids must now pass through the throttle and their flow rate can be reduced accordingly.

Where are throttle check valves needed?

In hydraulics, throttle check valves primarily offer the great advantage of regulating the flow velocity in both directions. In this way, hydraulic cylinders can be controlled more precisely overall. Within certain limits, parallel operation of linear and rotary drives can be realized easily and cost-effectively. For simple applications, synchronous controls can also be mapped in this way.

More about the stick-slip effect

If two solid bodies move against each other like a piston in a cylinder, a stick-slip effect can easily occur. This jerk is caused by a change in the acceleration of the piston in the cylinder. It can result from inconstant fluid pressure on the piston and then initially disrupt the cylinder function and eventually cause long-term damage.

Comparable stick-slip effects exist many times in everyday life. Do you remember the squeaking of chalk on the blackboard in school? Or do you know how tires squeal when you start up or brake? These are all stick-slip effects. They not only cause unpleasant noises, but also excessive material wear. This is naturally undesirable, especially in industrial plants.

Excessive wear here means high maintenance costs with a lot of downtime and, in the end, a shortened service life of the equipment. All this costs companies a lot of money. Small as they may be, throttle check valves prevent this effect and thus sustainably reduce process costs.

The throttle check valves from ARGO-HYTOS

You can find ARGO-HYTOS throttle check valves

• as built-in version,
• with housing for inline installation or 
• as a modular design with twin check valves.

With twin throttle check valves such as our models VS01-04/M, 2VS3-06 and VSO3-10/M, you get alternately pilot-operated check valves for fluid lines.

Here you can adjust volume flows in two separate passages. The adjustment is made precisely via open or concealed adjustment screws. The volume flow can be controlled by either the outlet or the inlet. The nameplate on the valve bodies shows you the valve functions and provides concrete support for correct installation. These dual flow control valves are available from ARGO-HYTOS in six variants for every application requirement.

The other flow control valves are available as built-in versions with different connection sizes or as inline models with ¼-inch connection including an optional check valve. The check valve can regulate a bypass flow or the fluid flow in series. In the data sheets for the respective valves, we show you all the characteristic data of the valves.

General information about throttle check valves and flow control valves

All of these valves require high fluid cleanliness for optimal operation in hydraulic applications. Our oil filters, ventilating filters, oil service equipment and dewatering systems help you achieve this cleanliness or ensure it permanently. Also make sure you use suitable working fluids. Mineral oils of classes HM and HV are best suited for our flow control valves in the hydraulic sector.

For all other fluids, we recommend close coordination with our expert consultants and the fluid manufacturers. This will ensure that the fluids do not affect the service life of your equipment. Furthermore, pay attention to the temperature and viscosity of the pressure fluids. Both values have a decisive influence on the effect of the pressure fluids in your plants.

Our flow control valves can be used in a temperature range from -30 °C to 120 °C, depending on the seal material. Above these temperatures, the pressure fluids rapidly decompose and the optimum operating properties rapidly decrease. Your equipment or drives will then function increasingly poorly and unreliably. In particular, check equipment seals regularly. Leaks lead to fluid losses and also to increased operating temperatures of the fluids.

Also, pay attention to the ambient temperature. Standard throttle valves are only designed for working and ambient temperatures around 50 degrees Celsius. Beyond that, damage to the valve seals can occur. If necessary, use special temperature-resistant seals around the valves. Our service team will be happy to advise you on these and other details. Or alternatively contact our local contacts.

ARGO-HYTOS always delivers what your company needs in hydraulics.

Valves such as throttle check valves form only a small part of our innovative product portfolio for companies in all industries. For over 75 years, we have been advancing industrial hydraulics and, for some time now, mobile hydraulics as well, with many innovations. As a medium-sized family-owned company, we employ more than 1600 people.

We develop individual high-quality components for your processes, such as throttle check valves, flow control valves and more. In the same way, we become your partner for the development of entire plants and individual solutions. Use our modular product range or talk to us for individual offers and solutions.

Together, we make many things better and continue to develop your products and processes. In this way, you gain the competitive advantages today that will drive your company forward tomorrow and in the future - with ARGO-HYTOS. We would be happy to advise you personally on specifications or product selection. To do so, use our online contact right now.