5521-E – Stand-Off, 5521

The AqMatic 5521-E Stand-Off (part number 1075354) is a precision spacing component used in 5521-series diaphragm valve assemblies, designed to maintain correct positioning of internal parts within the valve bonnet.

This stand-off functions as a fixed spacer within the valve assembly, helping establish proper distance and alignment between internal components such as the diaphragm plates, shaft, and spring. In 5521 isolated bonnet designs, maintaining this spacing is critical for consistent diaphragm lift, sealing performance, and valve response during operation.

The component is typically used during valve rebuilds or internal service, where wear, deformation, or incorrect spacing can lead to inconsistent cycling or sealing issues. It is not a universal spacer and must be matched to the correct 5521 configuration.

This part is commonly serviced alongside diaphragm plates, springs, and caps in systems that may also include V42 diaphragm valves and K53 series valves, often controlled through automated sequencing using stagers.