Westinghouse Air Pump Operation
When I was first building this pump, it took a while before I understood how these things work. For those of you that aren't familiar with these type pumps, my explanation below will hopefully help shorten this time for others.
Items are color coded to help identify them.
As Steam enters the pump, it travels to the Reversing Valve which is the vertical object (green) in the lower diagram. The Reversing Valve, when in its upward position, routes the Steam to the back side of the Shuttle Valve Sleeve which can be seen on the top diagram.
<<< Steam In
Once the Steam enters the back of the Shuttle Valve Sleeve, it forces the Shuttle Valve to the other side (front). The Steam input is also routed directly to the Shuttle Valve Sleeve, bypassing the Reversing Valve. With the Shuttle Valve in this position, the steam passages are open to the Top-Right/Bottom-Left cylinders.
Remember, the steam section is not cross-compounded, thus direct steam to both pistons.
As the Steam enters the Top-Right/Bottom-Left cylinders, it pushes the steam pistons to the opposite ends. The Exhaust is routed through the Top-Left/Bottom-Right passages. The Exhaust then goes to the Shuttle Valve Sleeve where the Shuttle Valve is already positioned to route the Exhaust out.
Once the steam pistons reach the opposite ends, the rightmost Piston Rod "pulls" down the Reversing Valve Rod/Piston. This shuts off the Steam from the back of the Shuttle Valve Sleeve and routes Steam to the front .
As the Steam enters the front of the Shuttle Valve Sleeve, it pushes the Shuttle Valve towards the back. This routes the Steam to the Top-Left/Bottom-Right cylinders.
With the Shuttle Valve in the back position, the Top-Right/Bottom-Left cylinders are routed to the Exhaust.
Once the right Steam Piston reaches the top, The Piston Rod pushes the Reversing Valve Rod/Piston upwards and the cycle repeats.
Questions or problems regarding this web site should be directed to [heydan "at"
danslocoworks "dot" com].