Thermostatic Steam Trap Manufacturer in saudi Arebia

KSA VALVE CONTROL INC is top quality  Thermostatic Steam Trap om saudi arebia  Thermostatic traps operate in response to the surrounding steam temperature. The operation and benefits of 3 different types are considered here – liquid expansion traps, bimetallic and balanced pressure thermostatic traps. Each operates in a different way and is suited to specific types of application.

Liquid expansion steam trap

This is one of the simplest thermostatic traps and is shown in Figure 11.2.1. An oil filled element expands when heated to close the valve against the seat. The adjustment allows the temperature of the trap discharge to be altered between 60°C and 100°C, which makes it ideally suited as a device to get rid of large quantities of air and cold condensate at start-up.

As discussed in Module 2.2, the temperature of saturated steam varies with pressure.

Figure 11.2.2 shows the saturation curve for steam, together with the fixed temperature response line (X – X) of the liquid expansion trap, set at 90°C.

It can be seen from Figure 11.2.2 that when the pressure is at pressure P₁, condensate would have to cool by only a small amount (ΔT₁), and trapping would be acceptable. However, if pressure is increased to P₂ then condensate has to cool more (ΔT₂) to pass through the steam trap. This cooling can only occur in the pipe between the process and trap, and if the trap discharge temperature remains constant, the process will waterlog.

Typical application

Because of its fixed temperature discharge characteristic, the liquid expansion trap may be usefully employed as a ‘shutdown drain trap’. Here, its outlet must always point upwards, as illustrated in Figure 11.2.3, to enable continuous immersion of the oil filled element. As the trap can only discharge between 60°C – 100°C it will only normally open during start-up. It can be installed alongside a mains drain trap which would normally be piped to a condensate return line.