Emergency Eyewash Station

Overview

An emergency eyewash station is a fixed safety fixture that immediately floods both eyes with a low-velocity stream of water to flush out corrosive chemicals, particulates or other irritants. It is a primary first-aid device wherever workers handle hazardous materials, and its design is governed almost entirely by the ANSI/ISEA Z358.1 standard: the unit must reach flushing flow within one second of activation, deliver at least 0.4 gallons per minute to both eyes, and sustain that flow hands-free for a full 15 minutes so the user can hold their eyelids open and roll the eyes during the rinse.

Water enters through a service Ball Valve and the Supply Riser, passes through the Flow Control Regulator regulator that pins the rate near the standard regardless of building pressure, and is brought to a safe temperature by the Thermostatic Mixing Valve. The Push-Flag Valve is the heart of the fixture: striking its paddle latches it fully open. Water then rises to the Spray Head Assembly, whose two aerated heads throw soft inward streams while their dust covers blow clear. Spent water collects in the Bowl Assembly and runs to drain. The whole fixture stands on its Mounting Stand and is marked by the Identification Sign so it can be located even with impaired vision.

How it works

In standby the valve is closed and the spray heads sit capped against dust. When a worker is splashed they reach the station within the ten-second/55-foot travel limit the standard sets, and strike the large Push Flag / Paddle with a hand, elbow or knee. The push rotates the stay-open stem past an over-center latch, so the valve stays wide open and the operator never has to keep holding it. Full inlet pressure drives water through the flow cartridge, which compensates for pressure to hold roughly 0.4 GPM, and through the mixing valve, whose thermostatic element proportions hot and cold to keep the stream tepid. The aerated heads convert the supply into a gentle laminar flow that will not further injure the eye, and the receptor bowl carries the overflow away. Flushing continues uninterrupted for the recommended fifteen minutes, after which the latch is released and the valve springs closed.