Dresser 5C15 Установка, эксплуатация и обслуживание - Страница 4

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GENERAL DESCRIPTION

ROOTS

Meters are manufactured in accordance with the

American National Standard specification ANSI/ASC-B109.3

for Rotary type Gas Displacement Meter. The meter operat-

ing temperature range is from -40°F to +140°F

(-40°C to +60°C).

ROOTS

Meters sizes 5C15 and 8C15 have a Maximum

Allowable Operating Pressure (MAOP) rating of 15 psig

(103kPa). Every meter is static pressure tested at the

factory at twice its MAOP (30 psig/206 kPa) and leak

tested at 125 percent of MAOP (18.75 psig/128.75 kPa)

in accordance with ASME Boiler Pressure Vessel Codes.

IMPORTANT: The maximum working pressure of a rotary

meter is limited by casing design. Meters should not be

installed where line pressure can exceed the Maximum

Allowable Pressure. Refer to the basic meter body

nameplate for the MAOP.

Meter accuracy is not affected by low or varying line

pressures. 5C/8C15 meters may be used satisfactorily for

pressures ranging from a few ounces to full MAOP. The

meter base rating is expressed in hundreds (C) of Actual

Cubic Feet per Hour (ACFH), or in Cubic Meter per Hour (m

Displaced volume measurement is completely independent

of the gas specific gravity, temperature, and pressure.

Displaced volume can be easily converted to volume at

Standard conditions for elevated pressure and varying

temperature by application of the Basic or Ideal Gas Laws.

Refer to a meter-sizing chart for capacity ratings at

elevated line pressures.

Major components of the meter are machined or cast from

aluminum for a combination of strength and weight

reduction. All aluminum parts are anodized, and the

measuring chamber and impellers are hard-coat anodized

for added corrosion and abrasion resistance.

Lubrication for the main bearings and timing gears is

permanent, and no oil should be added.

METER INDEX

Two index options are available. The customer specifies

the dial or odometer index when ordering the meter.

Readings are in ACFH (m

/h).

Figure 2 - Odometer Index

METER INSTALLATION

Piping configurations

Line mounted ROOTS

installed in either a Top (vertical), Side (horizontal), or

Bottom Inlet (vertical) configuration. The preferred or

recommended installation is a top inlet in a vertical pipe

line with gas flow downward. In a bottom inlet application,

a 60 Mesh screen is recommended in the inlet (bottom)

connection. Although the design of the impellers tends to

make the meter inherently self-cleaning, the top inlet

mounting allows gravity to pass dirt, pipe scale, or other

debris through the meter.

The installation of tees will allow the meter to be tested

while mounted in line using a transfer prover.

Do not install the meter lower than the discharge pipe

run to avoid accumulation of condensate and foreign

materials in the metering chamber. Use a screen or stainer

upstream of the meter to remove liquids and foreign

matter (pipe sealant, tape, weld slag, etc.) from the gas

stream. A 100 Mesh screen is recommended.

Do not install a lubricated gas valve directly before a

H).

meter, as excess valve lubricant or other foreign material

can stop impeller rotation.

If over-speed conditions can occur, a restricting flow

orifice plate should be installed 2 to 4 pipe diameters

downstream of the meter outlet. Contact Dresser Roots

Meters & Instruments for sizing, pricing and availability.

Warranty does not cover over-speed conditions.

Placing Meter in Line

1. Before installing a meter:

Make sure the upstream piping is clean. During

this procedure, use extreme caution and follow

recommended company procedures.

Remove the plastic protective caps from both

meter nipples prior to meter installation.

Insure the impellers turn freely and no objects or

contaminants are in the measuring chamber.

Figures 2 & 3 - The

5C15 and 8C15 may be

ordered for Top or

Bottom Inlet, with dial

or digital index. Internal

pipeline screens are

available.

Figure 3 - Dial Index

Meter sizes 5C15 and 8C15 may be