Pressure Resistance of Air Heaters
The pressure resistance of the air heater for models with partially exposed glass tube is maintained at 0.2 Mpa (approximately 2 kg/cm2) for safety.
Note that the pressure applied to the air heater during normal use is 0.05 MPa (50 kPa) or less. --> Air supply pressure data
If the source pressure of the compressor and piping pressure is 0.8 MPa or more, this pressure will not be applied as it is. There is always a valve for flow rate adjustment and when required to be used the pressure will be reduced by a few tenths by passing through the valve (see figure below).
Models such as PH type covered with the metal case may be used in-line, and there is a possibility of application of high air pressure to the entire heater case.
Therefore, the pressure resistance for such products is set at 0.6Mpa. We can manufacture heaters with higher pressure resistance if required.
Here pressure resistance means that the heater is not damaged, and not that there is no air leakage. In these heaters, glass cloth wound wire is often used as the lead wire, in this case, there is some air leakage from the gap of the cloth if high air pressure is applied. However, this leakage has been almost eliminated with the improvement of 2010 (special processing).
The above figure is an example of a simple use of the air heater. If we assume that the source of compressed gas is a compressor, the pressure is approximately 0.8 Mpa (8 atm).
However, if air with a predetermined flow rate is allowed to flow by throttling the flow rate adjustment valve, a large pressure difference can be maintained before and after the valve as shown in the figure above, and the pressure in the hose leading to the air heater is only about 0.3 atm.
Further, there is a slight drop in pressure after passing through the air heater, and the internal pressure of the air heater is 0.25 atm.
In this way, if air passes through locations where there is air flow resistance, a pressure difference can be obtained before and after such locations, and a pressure drop is achieved by passing the air through such locations.
That is, even when the air heater is connected to a high-pressure air source, the flow rate can be controlled using a flow rate adjustment valve, and air can be supplied to the heater by reducing the pressure to below 0.5 atm is possible.
When the air exits from the air heater, the pressure will be almost zero. It should be noted that the pressure referred to here is the relative pressure with respect to the atmospheric pressure.