These gauge/seal asssemblies feature 316 Stainless Steel gauges on heavy duty PVC diaphragm seals. The seal isolates the gauge from corrosive chemicals and idrty water, and also protects against pressure spikes.
Two models are available: The standard model has a Viton diaphragm and the seal and gauge is filled with glycerine. The chemical model features a Teflon diaphragm and the seal is filled with fluorolube, with a dry gauge.
The standard model is great for general purpose use, while the chemical model is specially designed for use with chlorine chemical feed systems.