VPP2-06-xV/xx-CE1017_Instruction manual for the use of_Gebrauchsanweisung_Návod k použití__29426400_2en_de_cz_09/2021
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Glossary of technical terms used
› A hydraulic mechanism is one in which energy is transmitted via the pressure energy of the working fluid
› Hydraulic accumulator is a pressure vessel, the inner space of which is divided by a flexible part (membrane, diaphragm) into two parts.
The upper part is filled with an inert gas (eg nitrogen) and the lower part is tightly connected to the hydraulic circuit. In the accumulator,
the compression of the gas by the pressurized liquid thus reverses the pressure energy of the liquid into deformation energy and thus
the energy is accumulated. Pressure vessels are dangerous elements and may only be protected against overload by certified valves.
› Volume flow Q is the amount of liquid in volume units that flows through a given cross-section per unit time
(m
3
s
-1
in SI units, l/min in practice)
› Cracking pressure – pressure value, set mechanically by the adjusting screw, when reached the valve opens
› Pressure relief valve compares the pressure value in the circuit against the set cracking pressure. If the set value (cracking pressure)
is exceeded, the valve opens by draining the working fluid from the circuit back to the tank, relieving the pressure-overloaded circuit
› Pressure is the force acting per area unit [SI unit is Pascal (1 Pa = Nm
-2
), in practice 1bar = 0,1MPa]
› Pressure level – adjustable cracking pressure range of the valve (e.g. “pressure level 16” has an adjustable pressure range from
0 to 160bar)
› Pressure valve – hydraulic valve, which serves to control the pressure in the circuit, the force on the piston rod of the hydraulic cylinder
or the torque on the output shaft of a rotary hydraulic motor
1. Use of the product
The VPP2-06 valve
is a directly operated hydraulic pressure relief valve, designed for installation into a block – in cavity QP2 (see Dimensions
chapter
6.2
Installation of the product) with connection thread M28x1,5.
The product is designed to set the maximum working pressure in the hydraulic circuit and protect the circuit against overloading due to pressure
peaks. It is usually connected in parallel to a pressure source (pump) or to an appliance that protects against overload.
Valves certified
according to Directive 2014/68/EU and related harmonized standards may be used with pressure equipment, e.g. pressure vessels
(accumulators). The valves are marked with the CE conformity mark and a Declaration of Conformity is issued for them.
2. Risks and restrictions of product use
DANGER
Maximum operating pressure
The valve may be used for a maximum pressure of 320 bar. If the maximum pressure is exceeded, there is a risk
of damaging the valve and if the compressive strength value of 480 bar is exceeded, the valve will rupture.
DANGER
Maximum volume flow
If the valve is used to protect pressure equipment, such as pressure vessels (accumulators) according to Directive
2014/68/EU and ISO 4126-1 standard, the maximum volume flow through the valve may only be set so that
the short-term overpressure in the circuit is not greater than 10 % above the set cracking pressure. The valve
dynamics depend on the kinematic viscosity of the working fluid (viscosity class and temperature). If the valve
reacts slowly, there is a risk of inadmissible pressure peaks and destruction of the pressure equipment.
WARNING
Tightening the valve into the cavity
The valve may only be screwed into a suitable and correctly manufactured cavity and must be tightened to the
specified tightening torque of 80 + 5 Nm. Otherwise there is a risk of leakage of the working fluid
and release of the valve by pressure.
CAUTION
Maximum operating temperature
The maximum operating temperature must not exceed the temperature range for the given type of sealing
material, otherwise seal tightness will be lost, and the working fluid will leak.
Seal material NBR: -30 ... +100 °C (-22 ... +212 °F)
Seal material FPM (Viton®): - 20 ... + 120 °C (-4 ... +248 °F)
CAUTION
Valve surface temperature
The surface temperature of the valve can exceed 100 °C (212 °F) due to the temperature of the working fluid
and pressure loss in the valve being converted into heat. Do not touch the surface of the valve while the circuit
is operating, even after switching off until it has cooled to a safe temperature. There is a risk of skin burns.
CAUTION
Working fluids used
The valves may only be used for common working fluids, especially hydraulic oils (see chapter 3. Product
description). The following are forbidden to use as a working fluid:
›water and aqueous solutions that cause corrosion and loss of valve function
›liquids that are highly flammable or explosive, which when heated through a valve can lead to fire
or explosion
›aggressive liquids (eg acids and hydroxides) that will cause valve damage and loss of function
