Since 1933 MIYAWAKI develops and manufactures high-quality equipment for a wide range of steam and condensate lines.


Ball Float Steam Traps belong to the family of mechanical traps. They operate on the difference in density between steam and water.

A ball float is connected with a lever to the valve and seat. Condensate will be discharged once it reaches a certain level inside the trap. Condensate is discharged continuously.


G11N & G12N Cast Iron Steam Traps for small and medium condensate loads
G15N Cast Iron Steam Trap for low pressure and large condensate loads
G3N, G5, G2 - G8 Ductile Cast Iron and Cast Iron Steam Traps for large condensate loads
G20N, G30 Ductile Cast Iron Steam Traps for medium condensate loads
GH3N - GH5, GH2 - GH8,
GH50, GH60, GH70
Cast Steel Steam Traps for large condensate loads
GH40, GTH12 Cast Steel Steam Traps for medium condensate loads
GC1, GC1V Stainless Steel Steam Traps for small condensate loads
GC20 Stainless Steel Steam Trap for medium condensate loads


  • All traps are equipped with stainless steel wear and corrosion resistant float, lever, valve and seat systems for a long and problem free operation
  • Each ball float steam trap is equipped with an air vent for venting air and gases at the time of start-up and during operation
  • The large capacity steam traps like G2-G8,GH2-GH8 use a double ported balance valve system, which is small in its physical size compared with the very high capacity of the traps
  • All traps are designed for quick and easy maintenance


Ball Float Steam Traps can be used in all process applications, like all kind of heat exchangers, tank and unit heaters and others, where condensate must be removed immediately after it forms

The type GC1 is especially designed for applications in the food, pharmaceutical and other industries with small condensate loads and the need for stainless steel bodies. It can be also installed for drainage of steam main lines.

Operating principle:

cold condensate

hot condensate

steam/hot air

On start-up air is quickly discharged through the thermostatic air vent (membrane or bimetal type). Cold condensate fills the steam trap body.

As soon as a certain water level is reached, the float rises and opens the valve. The cold condensate is discharged through the open valve and the open air vent.

When the condensate reaches saturation temperature, the air vent closes and condensate is discharged only through the main valve orifice.

The condensate forms a water seal inside the trap body, which prevents live steam loss at all times.

The opening degree of the valve is regulated by the water level inside the trap body. Condensate is discharged continuously.

As long as air enters the trap and accumulates at the top of the trap body, the temperature cools down a little bit and the air vent, which opens slightly below saturation temperature, begins to discharge the air from the trap.