Installation Without By-Pass; Meters Placed After A Regulator; Maintenance; Maintenance Of The Meter - DRESSER Delta Serie Mode D'emploi

SHUT DOWN:
• Slowly open the by-pass valve and then close the upstream
and downstream valves on the meter line .
• Carefully open the small bleeder valve V2 and depressurise
the meter . The pressure variation should not exceed 0 . 3 bar
per second .
• Some gas still inside the meter and the pipe, therefore suf-
ficient ventilation is required .
5.3 Installation without by-pass: See Annex 6
START-UP:
Begin with all valves closed .
• Slightly open the upstream valve to pressurise the meter line .
The pressure variation should not exceed 0 . 3 bar per second .
When the pressure is balanced, fully open the upstream valve .
• Slightly open the downstream valve . The valve should be
opened a small amount to maintain:
- The upstream pressure in the meter line .
– A low flow rate in the meter during the downstream pres-
surisation (approx . 5% Qmax) .
When the downstream pressure is balanced, the downstream
valve can be completely opened .
SHUT DOWN:
• Very slowly close the downstream valve and check that the
meter is no longer recording .
• Close the upstream valve .
• Slowly open the small bleed valve V2 . The pressure variation
should not exceed 0 . 3 bar per second .
• Some gas still inside the meter and the pipe, therefore suf-
ficient ventilation is required .

5.4 Meters placed after a regulator

Installation has to be done in accordance with the technical
manual of the specific regulator . During pressurisation and
depressurisation, insure that the pressure variation should not
exceed 0 . 3 bar per second .

6 Maintenance

6.1 Maintenance of the meter

Once installed, the meter does not require any specific atten-
tion except a periodical check or change of the lubricant filled
in the covers .
After start-up:
Natural gas: After the preliminary term of service, the lubricant
level should be checked .
Other gases: After a working period of 100 hours from commis-
sioning, the lubricant level should be checked .
If the lubricant level is appreciably low, if the lubricant is emulsi-
fied or if there is a chemical reaction between the lubricant and
the gas, the lubricant should be reassessed and changed to fit
the prevailing conditions .
Periodical change of lubricant:
The period between checks or changes of lubricant depends of
the operating conditions (pressure variation, flow rate . . . ) .
6
Natural gas: Under normal conditions, lubricant has to be
changed every 5 to 8 years . When the meter is used with ex-
tremely clean gas the period can be extended .
Other gases: Please consult us .
Use solvent and alcohol free product to clean the meter .
Repair must be done only by qualified personal . Afterwards a
tightness test with 1 . 1 x PS (Pmax) must be performed .
If used with wet gas, internal and external effect of corrosion
has to be checked regularly and in case of severe corrosion, the
meter has to be replaced .
Spare parts:
When changing pressure containing parts, ensure that spare
parts that comply with the PED are used .

6.2 Maintenance of optional equipment

6.2.1 LF and HF transmitters

These transmitters do not require any specific maintenance .
The function of the transmitters can be checked by comparing
the electronic index with the meter index .

6.2.2 Filter

If an increase of pressure loss is noticed, the filter should be
checked and cleaned/replaced before any maintenance on the
meter .