Neptune HP PROTECTUS III, Руководство по установке и обслуживанию

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Knuckle Valve
The knuckle valve sits behind the turbine measuring element. It is a rubber-faced disc that is
held closed with linkages. When the flow rate is low, the water does not have enough force to
overcome the knuckle valve. The water hits the face of the knuckle valve and is diverted to the
T-10 bypass. As the flow rate increases the water pushes the knuckle valve open. When the
water increases in flow rate and the knuckle valve transitions from closed to open, the meter
is transitions through a state know as crossover. After transitioning through cross over, the
meter is in a medium to high flow range.
The T-10 bypass continues to constantly measure flow. The T-10 bypass should always be
registering some flow as long as the flow rate is above the T-10’s minimum operating rate.
The turbine measuring element can register flow when the rate is medium to high.
UL / FM Basket Strainer
The strainer in the HP PROTECTUS III meter is a UL / FM-approved strainer specially designed
to handle fire service applications. The round style of the strainer allows debris to fall to the
bottom of the strainer housing. This is significant, because the meter must deliver the flow
rate required for a fire situation, even if debris has entered the meter. By having the debris fall
to the bottom of the strainer housing, it keeps the debris out of the line and does not
obstruct a large flow.
You can remove and clean the basket when necessary. There is an o-ring seal between the
strainer cover and the body to protect against leaking."Strainer Case O-Ring" on page 28.
HP PROTECTUS
®
III General Information
The following sections provide general information about the HP PROTECTUS III meter.
Operation
At low flow rates, all flow goes through the bypass meter. As flow increases, pressure loss
through the bypass meter increases, and the knuckle valve opens. This condition occurs
when a fire sprinkler system goes into operation and permits flow through the main turbine
meter. As flow decreases, reduced pressure loss closes the knuckle valve, and flow is again
directed through the bypass meter.
HP PROTECTUS ® III Installation and Maintenance Guide 3
Chapter 1: Product Description