Air valve technology is the heart of the air powered double diaphragm pump and determines reliability. Yamada holds three patents on its field proven valve and enjoys a superior reputation throughout the industry.

Unified Air Valve Concept
To simplify, Yamada offers two common size air valve assemblies within fives sizes of pumps (¾" & 1" pumps and 1½ ", 2" & 3" pumps) further reducing reassembly confusion and parts inventory. Other air powered double diaphragm pump manufacturers offer multiple air valve designs and revisions typically create maintenance rebuild issues, parts confusion, and obsolete inventory. Whether your pumps are functioning continuously or intermittently; at high or low pressure; using dirty of clean air; Yamada offers one field proven design.

Truly Non-Lubricated Air Valve
The patented air valve on all NDP series pumps never requires lubrication or pre-packing. The advanced design eliminates the need for external lubrication which can lead to pump fluid contamination and maintenance headaches.
Yamada is proud to be the originator of non-lubricated air valve technology for air powered double diaphragm pumps. Many of Yamada's competitors claim to offer a non-lubricated air valve.
Dependant on the competitor design, the air valve will probably require lubrication for continuous operation, or lubricator installation if moisture is present in the air system. These valves are pre-packed with grease and are truly non-lubricated.

Component Replaceable
All Yamada air valves can be restored with individual components, without requiring complete valve and housing replacement. many competitor air valves incorporate a complicated design which requires complete replacement of the valve assembly and housing, further increasing the cost of ownership.

Non-stalling
A patented non-centering, spring-assisted shifter is incorporated into every NDP series pump, ensuring the positive shift every time. The 304 stainless steel C-springs provide exceptional durability and longevity and are tested to last over 300 million cycles! the spring assist also aides in long dead head applications for a reliable start-up.