In order to flush away local bleeding during surgery with a medical instrument, the instruments are commonly provided with a flushing device. In order to be able to control an inflow and outflow of a flushing liquid, the instruments have a stopcock. In order to achieve the sealing action of the stopcock, the plugs of the stopcock have to be formed with a very high degree of precision. The known production processes for such plugs are very cumbersome and cost-intensive. This provides a plug for a stopcock and a stopcock and a method for producing a plug, by way of which the stated problem is eliminated. This is achieved in that a plug, with a grip part and a cone part, is formed in one part and can be produced in a single process step.

A rotary valve and a quick exhaust valve for a railway vehicle in which high sealability and operability at the time of valve opening and closing are ensured. Outflow/inflow ports (10, 11) and a discharge port (12) are formed in a valve body accommodating part having a spherical surface part or a tapered surface part formed on part of an inner periphery in a body (2), and a valve body (3) is rotatably inserted from an opening which is open from the valve body accommodating part. A spherically-shaped surface part or a tapered-shaped surface part is formed at a position opposing the spherical surface part or the tapered surface part, a plurality of through ports communicating the outflow/inflow ports or the discharge port and an attachment groove opposing the outflow/inflow ports in a direction crossing the through ports are formed, and a seal member is attached to the attachment groove.

In order to flush away local bleeding during surgery with a medical instrument, the instruments are commonly provided with a flushing device. In order to be able to control an inflow and outflow of a flushing liquid, the instruments have a stopcock. In order to achieve the sealing action of the stopcock, the plugs of the stopcock have to be formed with a very high degree of precision. The known production processes for such plugs are very cumbersome and cost-intensive. This provides a plug for a stopcock and a stopcock and a method for producing a plug, by way of which the stated problem is eliminated. This is achieved in that a plug, with a grip part and a cone part, is formed in one part and can be produced in a single process step.