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Technical Articles
January 19, 2016

Vented Ball Valves

Vented Ball Valves for Sodium Hypochlorite

ballheadAn optional vent is added to all True Blue trunnion ball valves specified for bleach applications. Without a vent of some sort, sodium hypochlorite would be trapped inside the ball whenever it is in the closed position, and give off gas (outgas). In the majority of poorly sealing valves, this gas wouldn’t be a problem…but due to the absolute bubble-tight seal of the True Blue ball valve, the trapped gas could eventually cause an explosion inside the ball.

The vent is designed as a hole through the side of the ball. When turned to the closed position, the hole allows any liquid or gas in the ball to flow freely in and out of the ball. Thus the liquid remains in contact with the upstream side, or it simply vents away downstream, depending on which direction the valve is installed.

NOTE: Plast-O-Matic recommends that the valve be installed so that the vent is directed back upstream.

To specify the vent, and eliminate the possibility of an explosive headache, use option #Z-MBV-VENT

bleach_open bleach_closed
 This “top view”” illustration shows the ball in the open position (the dashed line represents the handle) and shows the vent directed to the side. When open, the vent has no bearing on flow or performance.  This “top view” illustration shows the ball in the closed position (the dashed line represents the handle) and shows the vent directed to the process. This allows outgasses to vent harmlessly away. We recommend that Plast-O-Matic vented ball valves be installed to vent back upstream.

Ordering Information:

Note: Add #Z-MBV-VENT to the part number when specifying the valve. For complete information contact our Technical Sales group, or please click here to request a quote.