Emerson TG-0807 manual Installation and Operating Recommendations, Small Diameter Meter Tube

Technical Guide

DAN-LIQ-Turbine Meter-TG-0807

August 2007

INSTALLATION AND OPERATING RECOMMENDATIONS

For a turbine meter to perform without increased uncertainty and in a repeatable and accurate manner, the flowing stream must be free of rotational components. The internal assembly supports of a turbine meter offer a slight straightening effect, but additional flow straightening is normally required.

Generally, upstream flow straightening is effected through the use of adequate upstream straightening sections, which often comprise a set of straightening vanes or a tube bundle. Guidance on this subject is offered in the API Manual of Petroleum Measurement Standards, Chapter 5, Section 3.

For turbine flow meters of 2-inches and less, straightening vanes are not normally used. For most installations, twenty diameters of upstream pipe should be provided for adequate flow straightening. (See Figure 11)

Figure 11 - Small Diameter

Meter Tube

STRAINER

20D

MINIMUM

FLOW

5D

MINIMUM

TURBINE METER

D= NOMINAL PIPE SIZE

For line sizes 2-inches and larger, upstream flow straightening sections are normally supplied with straightening vanes. With this construction, the upstream straightening section need only be ten diameters in length.

Daniel supplies upstream and downstream flow straightening sections in either carbon steel or stainless steel, as required by the application. The standard design offered is the two-section tube, with a single upstream and single downstream straightening section. The upstream section contains the tube bundle, which is securely located within the pipe section. (See Figure 12)

Flow straightening sections may in fact be supplied in any configuration, with any line connection and to any specified length. In some installations, a three section flow straightening configuration is required. By using this configuration ready access to the straightening vanes is afforded. (See Figure 13)

Figure 12 - Two-Section

Meter Tube

10D

MINIMUM

FLOW

5D

MINIMUM

Figure 13 - Three-Section Meter Tube

LINE MODEL	TURBINE	METER TUBE
STRAIGHTENING VANE	METER
STRAINER

10D	5D
MINIMUM	MINIMUM
FLOW

METER TUBE	TURBINE	METER TUBE
FLANGE MODEL	METER
STRAIGHTENING VANE

D= NOMINAL PIPE SIZE

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