A system for controlling the mixing ratio of a multi-component mixture including a first pump connectable to a source of a first component and a second pump connectable to a source of a second component. The first and second pump being associated with at least one linear sensor for generating an output indicative of actual pump speed or shaft displacement of the pump. The system further includes a control circuit operative to utilize the output of the linear sensor of one of the pumps to generate a control signal for controlling the output of the other pump.

A heating system can include certain pressure sensitive features. These features can be configured to change from a first position to a second position based on a pressure of a fuel flowing into the feature. These features can include, fuel selector valves, pressure regulators, burner nozzles, and oxygen depletion sensor nozzles, among other features.

A device and method for chemicals to be fed into a water system, treating the water system as it enters, for example, a fire protection mains and/or fire protection systems (FPS) to protect and maintain the longevity of the water system preventing damages to the water system or enhancing the operation characteristics of the system. This device is a treatment system that may be installed as a portable or permanent device with chemicals such as, corrosion inhibitors, wetting agents, polymeric dispersants, biocides, biostats or other water chemical enhancing effects with means for injecting the chemicals into the fire protection system or a bypass feed system utilizing the fluid means without the need for any electricity. Activation of the pump occurs when water enters the FPS mains and FPS sprinkler system from an outside source. Valving is included to isolate the pump and drums, storage tank to prevent backflow from the FPS.

A dialysis service box for centralized control and plumbing arrangement of a dialysis machine is disclosed. The dialysis service box includes a plumbing arrangement having a supply inlet for supplying a fluid to the dialysis machine, a backflow preventer for preventing retrograde flow through the plumbing arrangement, a trap primer for maintaining a trap seal designed to prevent waste gases from flowing into the dialysis service box and a waste connection for allowing waste from the dialysis machine to exit. The dialysis service box can be universally installed to operate, control and adjust any dialysis machine that requires supply connection, waste connection, backflow preventer and trap primer, or any combination of the foregoing.

A dialysis service box for centralized control and plumbing arrangement of a dialysis machine is disclosed. The dialysis service box includes a plumbing arrangement having a supply inlet for supplying a fluid to the dialysis machine, a backflow preventer for preventing retrograde flow through the plumbing arrangement, a trap primer for maintaining a trap seal designed to prevent waste gases from flowing into the dialysis service box and a waste connection for allowing waste from the dialysis machine to exit. The dialysis service box can be universally installed to operate, control and adjust any dialysis machine that requires supply connection, waste connection, backflow preventer and trap primer, or any combination of the foregoing.

A system for controlling the mixing ratio of a multi-component mixture including a first pump connectable to a source of a first component and a second pump connectable to a source of a second component. The first and second pump being associated with at least one linear sensor for generating an output indicative of actual pump speed or shaft displacement of the pump. The system further includes a control circuit operative to utilize the output of the linear sensor of one of the pumps to generate a control signal for controlling the output of the other pump.

A spool switching valve device may include a columnar spool housing and spherical valve bodies. The spool housing includes first input port cavity portions, valve body movable portions and valve seat members. Each valve seat member has a through hole and includes a second input port portion. A second valve seat portion is provided to open and close the gap between valve body movable portion and the second input port portion. Each valve body movable portion includes an output port penetrating the side surface of the spool housing to communicate with the outside of the spool. Each valve seat mounting portion includes an engagement receiving portion suppressing the detachment of the valve seat members when the valve seat member is actually mounted. Each valve seat member includes an engagement portion fitted into the engagement receiving portion when the valve seat member is mounted to the valve seat mounting portion.