- Contractual requirement
- Rangeability or Turndown ratio
- Accuracy required
- Pressure requirement
- Calibration & maintenance requirement
- Size & weight
- Installation and maintenance constraints
- Operability
- Cost
- Gas quality
The ratio between Qmin and Qmax, i.e. the minimum and maximum flow rate
respectively for which the meter performs within the maximum permissible errors.
For various type of meters are as follows,
- Diaphragm meters 1: 150
- Rotary Positive Displacement meters 1:30 or Better
- Turbine 1:30 or Better
FILTRATION
Filtration at 50 microns or finer should be fitted to all metering system operating
at pressure above 500 mbar and 27 deg C.
CORRECTORS
Electronic volume correctors will be fitted to all meters operating between flow
range of 800 to 2500 scmd and for flow range above 2500 scmd Electronic flow
meter will be used.
GUIDANCE ON SELECTION
1. Commercial A (Up to 200 scm per day)
a. Normal Commercial :- Small Cafeterias, Restaurants, Caterers, SSI’s etc.
b. Small Commercial :- Office kitchen / Pantries.
c. Concessionary Commercial:- Temples, Charitable trust, Govt. Institution, etc
2. Commercial B (5000 to 25000 SCM per month)
Small scale commercial establishment and industries.
3. Commercial C (above 1000 scm per day)
Big hotels, commercial establishment , hospitals etc.
4. Commercial AC (Only for > 200 TR VAM)
Big hotels, commercial establishment , hospitals etc
5. Industries (Above 1000 SCM per day)
