Metal tube gas flowmeter

Product Overview

When the fluid in the VNLZ series metal tube gas flowmeter passes through an upright measuring tube from bottom to top, the float rises under the action of pressure difference. The height of the float rise represents the size of the flow rate, and is coupled and transmitted to the indicator through the magnetic steel in the float and the magnetic steel in the indicator, driving the pointer on the dial to rotate.

VNLZ series metal tube float flowmeterWhen the fluid flows from bottom to top through an upright measuring tube, the float rises under the action of pressure difference, and the height of the float rise represents the size of the flow rate. And it is coupled and transmitted to the indicator through the magnetic steel in the float and the magnetic steel in the indicator, driving the pointer on the dial to rotate.

【VNLZMetal tube gas flowmeterStructural principle

1. Structure

The VNLZ series metal tube gas flowmeter mainly consists of two parts: the measuring tube VNLZ indicator. The measuring tube includes conical tube or orifice plate, guide, stopper, float and other components, while the indicator includes magnetic follow-up system, pointer, dial, circuit and other components.

2. Working principle

The measured medium flows through the measuring tube from bottom to top, generating a differential pressure at the upper and lower ends of the float to form an upward force. When the upward force acting on the float is greater than the weight of the float immersed in the fluid, the float rises, and the annular gap area increases accordingly. The fluid flow velocity at the annular gap rapidly decreases, and the differential pressure at the upper and lower ends of the float decreases. The upward force acting on the float decreases until the upward force is balanced with the weight of the float immersed in the fluid. The float stabilizes at a certain position, and the height of the float position immediately corresponds to the flow rate of the measured medium.

The float is equipped with magnetic steel, and when the float moves up and down with the medium, the magnetic field changes with the movement of the float.

a. ForOn site typeThe coupling between the follower magnet in the local indicator and the magnet inside the float causes rotation, while driving the pointer to indicate the current flow rate through the dial.

b. Forintelligent typeThe rotation occurs due to the coupling between the follower magnet in the intelligent indicator and the magnet inside the float. Simultaneously driving the sensing magnet and pointer, the magnetic field changes are converted into electrical signals through a magnetic sensor. After A/D conversion, digital filtering, temperature compensation, microprocessor processing, D/A output, and LCD display, the instantaneous flow rate and cumulative flow rate are displayed.

Characteristics of VNLZ Metal Tube Gas Flow Meter

Suitable for flow measurement of small caliber and low velocity media

● Reliable work, minimal maintenance, and long lifespan

● Low requirements for straight pipe sections

A wider traffic ratio of 10:1

● Dual row large LCD display, optional on-site instantaneous/cumulative flow display, can be equipped with backlight

● Single axis sensitive indication

● Non contact magnetic coupling transmission

All metal structure, suitable for high temperature, high pressure, and highly corrosive media

● Can be used in flammable and explosive hazardous environments

● Optional two-wire system, battery, AC power supply mode

● Multi parameter calibration function

Equipped with data recovery, data backup, and power down protection functions

Technical parameters of VNLZ metal tube float flowmeter

● Measurement range:

Water (20 ℃) 1~200000I/h

Air (20 ℃, 0.1013MPa) 0.03-4000/h

Range ratio: Standard type 10:1 Special type 20:1

Accuracy: Standard Type 1.5 Special Type 1.0

Pressure rating: Standard type: DN15~DN50 4.0MPa DN80~DN200 1.6MPa

Special type: DN15~DN50 25MPa DN80~DN200 16MPa

The pressure rating of the jacket is 1.6MPa

Special types should be negotiated with the manufacturer before selection and ordering

Pressure loss: 7kPa~70kPa

● Medium temperature: Standard type: -80 ℃ to+200 ℃; PTFE：0℃～85℃

High temperature type: up to 400 ℃

● Medium viscosity: DN15: n<5mPa. S (F15.1~F15.3)

n<30mPa. S(F15.4～F15.8)

DN25：n<250mPFa. S

DN50～Dn150：n<300mPa. S

● Environmental temperature: LCD type -30 ℃~+85 ℃

Pointer type -40 ℃~+120 ℃

● Connection form: Standard type: DIN25001 standard flange

Special type: Any standard flange or thread specified by the user

● Cable interface: M20 × 1.5

Power supply: Standard type: 24VDC two-wire system 4-20mA (10.8VDC~36VDC)

Communication type: 85-265VAC 50Hz

Battery type: 3.6V@4AH Nickel-metal hydride battery

● Alarm output: upper or lower limit instantaneous flow alarm

Standard type: open collector output (maximum) 100mA@30VDC Internal impedance100 euros)

Special type: Relay output (maximum contact capacity) 5A@250VAC )

● Pulse output: Accumulated pulse output, with a minimum interval of 50 milliseconds

LCD display: Instantaneous flow display value range: 0-50000

Accumulated traffic display value range: 0~

● Protection level: IP65

Explosion proof mark: intrinsic safety type EXiaIICT4 explosion-proof type ExdIICT4

after-sales service
The first-time installation engineer can go to the site for service. If there are quality problems with the product during the warranty period, it can be returned or exchanged. If the customer receives a fault call and cannot solve it on the phone, technical personnel will be arranged to arrive at the site within 48 hours (except for force majeure factors). Saide Instrument is dedicated to serving you!
Shaanxi Saide flowmeter contact information: Mobile: Zhang Wei

related parameters