Total Control Systems 700-LP Series, Инструкция по установке, эксплуатации и обслуживанию

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Meter Selection
The flow meter must be carefully chosen from the Meter Selection factors in the Engineering Manual. The meter
must be selected based on the operating system and product characteristics. System variables include flow rate,
temperature and pressure. The product characteristics include the material compatibility, lubricity, viscosity,
suspensions, pH, and whether the product can congeal, crystallize or leave a dry film. Failure to select the correct
flow meter may result in system failure or serious injury.
Air or Vapor Elimination
In any system where the tank may be completely drained or multiple products manifold into one metering system,
the possibility of air or vapor being present increases. The solution is an air or vapor eliminator located before the
flow meter to vent the air or vapor from the system before it can be measured. Air or vapor elimination is required
for all weights and measures regulatory approvals in custody transfer applications.
System Recommendations
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 or foundation
2) The inlet and outlet piping must be securely supported, in a manner to not 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 full 2‖ pipe diameter 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 restrictions.
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 vapor eliminator to be installed directly to the meter. It can be installed upstream
from the meter. For effective operation of the vapor eliminator, it should be mounted between the meter and any
valves, tees or any other potential places where air or vapor 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
Most liquids will expand and contract with temperature. This is particularly true for LPG. 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.