FAQ-Product
The type SV02 is only partially suitable here. This valve is really only approved for gases. If condensate may be contained here, we recommend a safety valve which is approved for gaseous and liquid media.
If valves are too large, the function is guaranteed, depending on the application, it can happen that the valve gets into a so-called flutter state and does not open completely, since the small stroke is already enough to reduce the overpressure. This is accepted at very low power quantities, as there are no smaller nominal diameters for safety valves. It is important that the operating pressure is far enough from the opening or closing pressure to ensure closing after triggering.
ATTENTION:
Valves that are too small do not manage to dissipate the required power, resulting in a further increase in pressure!
In the case of a safety valve with bellows, the intrusive back pressure has no effect on the closing pressure.
Propotional stroke safety valves open Propotional to increase pressure. A full-stroke safety valve opens abruptly after response within a 5% increase in pressure.
In the case of full-stroke valves, there is an additional requirement that the proportion of the stroke until sudden opening (proportional safety valves according to AD2000-A2) must not exceed 20% of the total stroke. A normal lifting safety valve is a safety valve that achieves the stroke required for the mass flow to be discharged within a pressure increase of a maximum of 10% after response (start of stroke).
The operating pressure is the working pressure of a plant or system under normal circumstances. The operating pressure is ideally 5% below the closing pressure of a safety valve.
Our safety valves have an internal tightness of 10-4 mbar l/s.
A combined solution safety valve with rupture disc is possible, but must be requested and designed on a case-by-case basis.
Unfortunately, we cannot take back safety valves.
These are TÜV component-tested safety valves, i.e. they are manufactured, adjusted and sealed depending on the customer's order.
A return is therefore not possible.
The opening pressure is also called the blow-off pressure and is the point at which the safety valve reaches the maximum lift for the required mass flow to be discharged. This is normally a maximum of 10% above the set pressure for normal lift safety valves and 5% above the set pressure for full lift safety valves.
The alignment of the drain of the corner safety valves is not freely rotatable but results when screwing in.
According to regulation AD2000-A2, the diameter of the infeed line may not be smaller than the diameter of safety valve d0 due to pressure losses.
No. Safety valves are ALWAYS delivered preset and sealed at the factory. Therefore, please always inform us of the desired setting pressure when ordering. This cannot be changed afterwards.
Oversizing can lead to an unstable opening and closing behavior of the SV. Therefore, a correctly dimensioned safety valve should always be used accordingly for the application.
The code letters used for safety valves indicate the media for which the specific safety valve is permitted.
Here is an overview of the individual code letters:
- H = suitable for heating systems in accordance with DIN EN 12828 and DIN 4751
- D = suitable for steam
- F = suitable for fluid media
- G = suitable for gaseous media
- W = suitable for water heater systems in accordance with DIN 4753
- F/K/S = for mounted pressure vessels and vehicle tanks with liquid, dust and granular goods
Basically possible – but must always be considered on a case-by-case basis. A PTFE seal is recommended because it has a low probability that the seal will be pulled into the line by the vacuum. The PTFE seal, on the other hand, is not soft-sealing, so it has a poorer tightness than soft-sealing seals. Here it is important to clarify which vacuum tightness is required of the end user – in the form of concrete figures. This number can be checked/tested (at an additional cost). Another point to clarify is where the vacuum is due – entry or exit. In case of vacuum at the outlet, a bellows version is recommended in any case. Here, however, it must be noted that this also causes a vacuum at the seat, which can lead to leakage. Must also be considered on a case-by-case basis. Furthermore, the size of the valve and thus the line cross-section do is also a decisive point. With a smaller do, the probability that the seal will be pulled in is correspondingly lower (since the sealing surface is smaller) – with a larger do, the probability is correspondingly higher.
The set pressure or response pressure is the pressure at which the safety valve starts to open to blow off the pressure. This is the pressure set for the safety valve by us, your suppliers. The set pressure is subject to a tolerance of (+/-3%) or, for valves under 3 bar, (+/- 0.1) bar (in accordance with DIN EN ISO 4126-1).
The leak rate is 1 x 10-4 mbar x l/s
The bellows protect the spring and the sliding parts of the safety valve from the influences of, for example, sticky or highly viscous media and thus have a longer durability.
Set pressures of the safety valves are only possible in one place after the decimal point.
Safety valves are designed as the last safety instance of a system and are not designed to dissee or regulate medium regularly. In this case, for example, an overflow valve can be used. These overflow valves are specially designed for such an application and their task lies purely in the control range of a system.
The closing pressure is the pressure value at which the safety valve is completely closed again after it has blown off the excess pressure. This value is 20% below the set pressure for liquid media (the value is 0.6 bar below it for a set pressure <3 bar).
For gaseous media, the value according to AD2000 is 10% below the set pressure, and 15% below according to DIN EN ISO 4126-1 (at a set pressure < 3 bar the value is 0.3 bar below the set pressure).
We do not have heating jackets for safety valves or overflow valves in our range.
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