Spring loaded check valves have a minimum movement pressure that is necessary for overcoming the effects of the spring
10 March 2021
The spring check valve, which can be found in the Intertubi catalog, certified according to EN 10204 / 2.1, represents an important solution by merging the excellent closing characteristics provided by the spring with high versatility at the time of installation.
The main components of the spring check valve
The spring check valve consists of a series of fundamental components for its operation. In particular, the components characterizing the AURORA model are: - body: is the external structure of the valve and is made of AISI 316 stainless steel; - lid: plays a complementary role to the body and is realized in the same material; - disc: it is controlled by the spring and performs the function of retaining; - sealing: is made of polymeric material, PTFE or FKM; - gasket sealing disc; - spring: it is the element that guarantees the closing force; - rod: connected to the closing disc; - gasket: Made of polymeric material, usually PTFE.
The operation of the spring check valve
The operation of this type of valve is very simple. When the fluid reaches such a pressure to overcome the elastic force generated by the spring, the valve opens and guarantees the flow. Instead, when the pressure value falls below a minimum value, you get the opposite effect and the valve blocks the flow passage.
Optimal operating conditions of these valves
As you can read on the Intertubi catalog, the spring check valves has temperature and pressure values to be respected to ensure proper operation. In particular, the temperature must be maintained within an interval between -250 ° C and 180 ° C. The pressure, on the other hand, is characterized by a maximum value of 16 kg / cm2 and a minimum opening pressure of 0.13 bar. Respect for these conditions not only allows you to work efficiently, but also guarantees a longer life of the component over time, especially in relation to the gaskets in polymeric material.
The materials for sealing
As seen previously, the polymeric materials used for the realization of the sealing are the PTFE and the FKM.
What are these materials? The PTFE, abbreviated for polythetrafluoroethylene, is a material known mainly with the commercial name of Teflon, or the material commonly used as a non-stick coating in the pans. Its main features, in addition to the anti-adherence, are the complete chemical inertia, thermal resistance (resists up to about 260 ° C, fire resistance and insolubility in water. FKMs, acronym used to indicate fluorinated elastomers, are synthetic technopolymers characterized by high chemical resistance and, based on the degree of cross-linking obtained, can be more or less resistant to high temperatures.
On the basis of these properties it is easy to understand why the choice falls on these two polymeric materials: in fact, to guarantee high temperature resistances is not easy and is not characteristic of all polymers.