APPENDIX E. LIQUID FLOW MEASUREMENTS AND CAPABILITIES OF THE SECONDARY TRANSFER TEAMS USING TURBINE FLOWMETERS

TM 9-4931-456-14-1

APPENDIX E

LIQUID FLOW MEASUREMENTS AND CAPABILITIES OF THE

SECONDARY TRANSFER TEAMS USING TURBINE FLOWMETERS

The position of the float, therefore, indicates the rate of

E.1 Purpose and Scope

flow. These flowmeters are generally designed with a

This appendix provides information on the operation of

linear relationship between the rate of flow and the

turbine flowmeters as a standard in the calibration of

position of the float. The usable range of a variable

liquid flow measuring instruments. It is not to be used

area flowmeter is from 10 percent to 100 percent of its

as a calibration procedure, but may be used as a guide

maximum capacity. For best repeatability, the range

for training in the use of the turbine flowmeter.

should be limited to 20 percent to 100 percent of

maximum capacity. These types of meters are sensitive

E.2 Specifications

to changes in fluid density and viscosity. Since the

The flow range is 1.0 to 50 gallons per minute,

position of the float in a variable area flowmeter is

approximately 400 to 20,000 pounds per hour.

dependent on the density and viscosity of the fluid as

well as the rate of flow, the fluid used must have

E.3 General Instructions

properties similar to the fluid to be metered by the test

The rate of flow in gallons per minute is computed from

instrument.

the measurements made with the flow transfer

A second type of flowmeter is a turbine flowmeter that

standards. The rate of flow in pounds per hour is

has its own indicator, or can be read with an available

computed from the basic measurements and the

frequency counter. The frequency output of turbine

specific gravity of the fluid at operating temperature.

flowmeters is proportional to the rate of flow. For best

The flow transfer standards are precision instruments

repeatability, the test instrument should be limited to a

consisting of two ranges of turbine flowmeters with an

range of 10 percent to 100 percent of maximum

overall range of 1.0 to 50.0 gallons per minute. Each of

capacity. Other types of liquid flowmeters can be

the turbine flowmeters provides flow measurement over

calibrated, provided their range and operational fluid is

a 0.5 to 30.0 centistoke viscosity range with an accuracy

compatible with the flow standards. Refer to the test

of +0.35 percent of indicated volumetric flowrate. Each

instruments manual for specifications and operational

flow transfer kit contains, in addition to the flow

instructions.

standards, flow straightening sections and a digital

indicator.

E.4 Equipment Required

The operation and data collection procedure for the two

Table E-1 lists equipment required for calibration

ranges of turbine flowmeters is identical. The range of

performance checks and adjustments. Refer to it for

operation is initially determined and the appropriate size

specific item identification and specifications for

standard flowmeter installed in series (with arrow

selection of alternate equipment.

pointing in direction of flow) with the test instrument.

Verify that the test instrument is in good physical

Install the filter provided upstream of the 1/2 inch meter

condition, clean, and free from defects that would impair

prior to operation of the fluid source. The throttling

its operation (such as nicks on the float and bent float

valves on the fluid source (test stand, etc.) must be

extension, and if the test instrument is a variable area

closed at the start of the calibration to prevent

flowmeter). Other types of flowmeters will generally

overranging and subsequent damage to the standard

have erratic output after damage occurs.

flowmeter. Prior to a calibration run, the fluid in the test

If the test instrument has an accessory indicator, verify

stand must be checked for cleanliness and changed if

that the accessory is in acceptable condition and is

contaminated.

adjusted according to the manufacturer's instructions.

The majority of the flowmeters requiring calibration will

Inspect the fluid in the fluid source (test stand, etc.) for

be variable area flowmeters consisting of a float in a

cleanliness.

If any dirt or entrained particles are

tapered glass tube. The float assumes a position in the

present, the fluid must be drained, the system must be

glass tube where the exposed cross sectional area of

the tube has a direct relationship with the rate of flow.

E-1