Among the equipment of steam heating systems, a significant role belongs to condensate drains and pressure reducing valves. Let's consider the first ones using the flt17 steam trap as an example. Among the latter, we will select spring-loaded pressure reducing valves for steam for review.
Float steam trap
The FLT-17 float steam trap is used in all types of medium and low pressure steam systems. It is often installed in dryers, heating units with heat exchangers, vessels with a steam "jacket" and in other devices where condensate must be removed continuously. The condensate is discharged immediately after it has formed, the thermostatic air valve is responsible for venting the air.
Insensitive to sudden changes in flow and pressure FLT-17 steam trap works with media with temperatures 198 ° C (short time up to 250 ° C). It allows a differential pressure of 4.5 bar, 10 bar and a maximum of 14 bar. The FLT-17-НС model has an increased capacity. As a standard, the unit is mounted horizontally and needs thermal insulation when installed outside buildings.
Spring-loaded steam relief valve operation
Steam enters the chamber through the flange hole. The chamber and the cylinder are connected by a tube. The steam "presses" on the spool, then through the tube it enters and acts on the piston equipped with a sealing ring and a rod, which in turn is connected to the spool. When the piston moves up or down, the spool rises or falls and thereby changes the pressure and the amount of steam entering the heating system.
The area of the piston and the spool hole is the same, therefore, a change in pressure in the adjacent chamber does not affect the "openness" of the latter. When the pressure on the spool from above rises, it is transmitted through the piston to the spindle, the position of which in the first crosshead is adjusted by the flywheel. The first traverse is bolted to the second. When they are lowered at the same time, the spring is compressed.
When the steam pressure on the spool from above decreases, the spring is expanded, as a result of which both traverses, the piston, the spindle, and the spool rise. This increases the steam inflow and the pressure downstream of the reducer is restored. It is known that steam reducing valves will work stably when the initial pressure differs from the final one by no more than 5-7 times.
