Trofimoff valve

The Trofimoff slider (also Trofimov, Trofimov, Troffimoff or trofimof ) is a featherless pressure compensating piston valve for steam engines (especially steam locomotives).

The development of this spool valve design is not exactly follow. Supposedly it was developed in the 1920s in Germany, but the patents shall be then gone to the Soviet state railway. Other sources speak of a development of Bulgarian railway engineers.

The Trofimoff slider consists of a shifter rod, the displaceable thereon slide bodies and the two support plates. During the last trip, the slider body are pressed by the steam pressure on the support plates and work as normally spool. If the steam supply shut or closed with a steam locomotive, the controller, the vapor pressure falls off, the slider body remain because of piston ring tension in the inner dead center near the cylinder center stand. The slide rod moves without touching the valve body with the support plates attached to their continued back and forth. A perfect pressure balance and making it a perfect idling of the steam engine / locomotive is given.

The secured to the slide rod supporting plates also bear a piston ring. This dampens the " closing" the movable valve body. In narrow-gauge locomotives ( for example, the DR series 99.23-24 ) these piston rings are not present. You hear these locomotives during the transition from idle to load ride the characteristic clicking sound when you close the slider. This piston ring on the support body is a further development of the then RAW Meiningen.

That's not the entire cylinder block of the engine needs to be replaced in case of damage, the slides run into special sockets. The slide connector has two parts and in each case is pressed from the front and the back of the cylinder block. With special rigs this socket can be drilled repeatedly during repair. The last picture of the impact of the two bushing halves and rectangular openings are visible at the rear. These are the Dampfeinströmöffnungen. Through the front oblique slits, the steam flows to the plunger of the steam engine. The front portion, outside the slide sleeve is referred to as outflow box and flows through exhaust pipe, the riser pipe and the blast pipe head centrally below the stack of the locomotive. The slider body control by their motion ( reciprocal opening and closing of the oblique slots ) the gas exchange of the steam engine.

• Steam machine technology
• Steam locomotive technology