Protection From Debris - Total Control Systems 700-20 Engineering Manual

Control Valves
Safety and isolation valves should be used throughout the metering system. In any pumping
system where there is one (1) pump and multiple flow meters, a digital or hydro-mechanical
Rate-of-Flow control valve must be used at each flow meter to prevent over speeding of the flow
meters.
Best Plumbing Configuration
1). Flow meter must have secure mounting to a riser stand or the foundation.
2). The inlet and outlet piping must be securely supported, in a manner of not to allow pipe
stress on flow meter.
3). System should be designed to keep the flow meter full of liquid at all times.
4). System piping should have the same full pipe diameter or larger as the flow meter,
throughout the metering system to allow for minimal pressure loss.
5). The pipe should be laid out as straight as possible to reduce pressure loss from flow
restriction.
6). The meter and piping must be installed in such as way as to avoid accidental draining of the
meter. Meter inlet and outlet should be lower than the associated system plumbing (sump
position).
7). It is not necessary for the air eliminator to be installed bolted directly to the meter. It can be
installed upstream from the meter. For effective operation of the air eliminator, it should be
mounted between the meter and any valves, tees or any other potential places where air may
enter the system.
8). The metering system should include a means for calibration.

Protection From Debris

On new installations, care must be taken to protect the meter from damage during start-up. It is
recommended to put a strainer before the meter. Damage may result from the passage through
the meter of dirt, sand, welding slag or spatter, thread cuttings, rust, etc. The insertion of a spool
(a flanged length of pipe equal in length to the meter and accessories attached to the meter) in
place of the meter until the system is flushed, temporarily bypassing the plumbing around the
meter, will also protect the meter from debris. Once the system has run "clean" for a period of
time the meter may be reinstalled or protective devices removed.
Thermal Expansion
As with most liquids, they will expand and contract with temperature. In any system where there
is a chance for liquid to be captured between closed valves without relief, thermal expansion will
likely occur and create dangerously high pressures within the system. Care should be taken in
designing the system in which thermal shock may occur by implementing Pressure Relief Valves
or Thermal Expansion Joints in the system design.
When product is trapped within the system, the pressure will increase by 126 PSI (8.69 BAR) for
every one (1) temperature degree increase.
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