Orifice Flow Meters

High Accuracy Orifice (Meter Run Assembly) High Accuracy Orifice

Name: High Accuracy Orifice (Meter Run Assembly)
Brand: Daehan Instruments

MODEL : DHOF-H

A high accuracy orifice manufactured as a single assembly of Weld Neck orifice flanges, a meter run tube (L = 17Di) and a flow straightener. It targets an accuracy within ±0.3% on calibration (Calibration) and follows the ASME B16.36 orifice flange standard.

Product Overview

High Accuracy Orifice (Meter Run Assembly)

DHOF-H

The high accuracy orifice assembly (DHOF-H) is an assembly comprising orifice flanges, a meter run tube and a flow straightener.

Model DHOF-H□: used with the DHOF-H□ orifice plate, complete with Weld Neck flanges, meter run tube and flow straightener. As a meter run tube type, the DHOF-H□ is supplied only as an assembly (Assembly).

Accuracy 0.25% / 0.3%Meter run L = 17Di1B ~ 32B (25A ~ 800A)ASME B16.36

English description

These flanges & meter run tube, flow straightener Include high accuracy Orifice Assembly. They are available in the following types. Model : DHOF-H - Used with Model DHOF-H orifice plate with weld neck flange, meter run tube, flow straightener, etc. Meter run tube type. DHOF-H are only Assembly.

Measurement principle

Differential-pressure structure and flow relationship

Meter run configuration: upstream 12Di (straightener 2Di @ 10Di) · downstream 5Di · L = 17Di

The total meter run length L is 17Di (Di: pipe inside diameter), made up of 12Di upstream and 5Di downstream.

In the upstream section, a flow straightener of length 2Di (selected from Tube Bundle, Etoile, AMCA, K-Lab and NEL) is installed 10Di from the orifice to condition the flow entering the orifice.

The differential pressure taken from the orifice flange taps is measured by a transmitter (integral or separate), with an output of 4~20mA or 1~5V.

Types · model configuration

Specification comparison by model

Item	DHOF-H High accuracy orifice meter run assembly
Features	High accuracy
Turndown	4:1
Materials	Plate: STS304, STS316, Inconel, Monel, Hastelloy, Teflon · Flange: C.S, STS304, STS316, Inconel, Monel, Hastelloy, A182 F11, F22, F51
Connection	Flange 300#, 600#, 900#, 1500#
Applicable piping	2B ~ 24B (50A ~ 600A) Pipe & Duct
Standards	ISO5167-2
Accuracy	Within ±0.3% on calibration (In less than ±0.3% calibration)

Technical Specifications

Detailed conditions are confirmed at quotation.

Item	Value
Accuracy (1B ~ 20B, 40A ~ 500A)	0.25%
Accuracy (22B ~ 32B, 550A ~ 800A)	0.3%
Turndown (Turndown Range)	4:1
Nominal pipe size	1B ~ 32B (25A ~ 800A)
Meter run length	L = 17Di (12Di upstream, 5Di downstream) · flow straightener length 2Di, located 10Di upstream of the orifice
Flange rating (Flange Rating)	ASME(ANSI) 300#, 600#, 900# · Standard: ASME B 16.36
Flow calculation standard	ISO5167-2003, ASME PTC, AGA3, JIS Z 8762, KS A 0612
Applicable standards (Regulations)	ISO5167-2
Flange material	Carbon steel · 304(L)SS, 316(L)SS · Ni, Cr, Mo Alloy steel (A182 F11 to 91)
Plate material	304(L)SS, 316(L)SS · Ni, Cr, Mo Alloy steel (A182 F11 to 91) · Inconel, Hastelloy, Monel etc
Meter run tube material	A106 · 304(L)SS, 316(L)SS · Ni, Cr, Mo Alloy steel (A335 F11 to 91)
Tap connection 1 (threaded directly into flange)	1/2NPTF, 3/4NPTF, 1/2SW, 3/4SW
Tap connection 2 (nipple connection)	1/2NPTM, 3/4NPTM, socket weld, butt weld or flange
Flow straightener	Tube Bundle, Etoile, AMCA, K-Lab, NEL
Transmitter	One Body (integral) / Separation Type (separate)
Output	4 ~ 20mA / 1 ~ 5V / etc

Standards

ISO 5167-2 (2003)
ASME B16.36
ASME PTC
AGA 3
JIS Z 8762
KS A 0612

Installation requirements

Straight run and installation notes

The meter run assembly (upstream 12Di + downstream 5Di = 17Di) is connected to the piping by flanges at both ends.
The DP taps are either threaded directly into the flange (1/2 · 3/4 NPT F, 1/2 · 3/4 SW) or connected by nipple (1/2 · 3/4 NPT M, socket weld · butt weld · flange).
The transmitter can be ordered as integral (One Body) or separate (Separation Type).

Ordering information (How to Order)

You can request a quotation by combining the model codes.

Model

DHOF-H

High Accuracy Orifice Assembly

Nominal Pipe Size

(size)

Pipe size in inch or mm

Flange Rating

30	300#
60	600#
90	900#
O1	Option

Plate Material

4(L)S	304(L)SS
6(L)S	316(L)SS
I6	Inconel 600
HS	Hastelloy-C 276
O2	Option

Flange Material

CS	Carbon Steel
4S	304(L)SS
6S	316(L)SS
11	A182 F11
12	A182 F12
22	A182 F22
51	A182 F51
91	A182 F91
O3	Option

Meter Run Tube Material

CS	Carbon Steel
4S	304(L)SS
6S	316(L)SS
11	A335 P11
12	A335 P12
22	A335 P22
51	A335 P51
91	A335 P91
O4	Option

Diff' Pressure Taps

0	MFR STD
1	NPT 1/2
2	NPT 3/4
3	SW 1/2
4	SW 3/4
O5	Option

Flow Straightener

T	Tube Bundle
E	Etoile
A	AMCA
K	K-Lab
N	NEL
O6	Option

Transmitter

O	One Body
S	Separation Type
O7	Option

Output

A	4 ~ 20mA
V	1 ~ 5V
R	etc

Download Documents

Product Catalog PDF

PDF

High Accuracy Orifice (Meter Run Assembly) Datasheet PDF

Printable datasheet with the specifications, dimensions and ordering information on this page (same content as the web page, generated automatically)

PDF

Orifice catalog (High Accuracy Orifice DHOF-H)

p.9-10 High accuracy orifice description · meter run drawing · specifications · ordering codes · 17 pages

PDF

General Product Catalog 2024

p.11 High Accuracy Orifice DHOF-H· 23p

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Tell us the pipe size, fluid, pressure / temperature and flow range, and we will propose a suitable model and a flow calculation sheet.

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