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Darhor Solenoid Valves


What's is the solenoid valve
The solenoid is an electromagnetic part of a valve, comprised of a coil, coretube, core and enclosure. Darhor' Vdarhor brand offers the worlds largest selection of 2-, 3- and 4-way solenoid valves, designed to handle the most demanding fluid control applications.

2-way. One inlet and one outlet, and are used to permit and shut off fluid flow. The two types of operations are “Normally Closed” and “Normally Open”.
3-way.These valves have three pipe connections and two orifices. When one orifice is open, the other is closed and vice versa. They're commonly used to alternately apply pressure to and exhaust pressure from a valve actuator or a single acting cylinder. These valves can be normally closed, normally open or universal.
4-way.These valves have four or five pipe connections, commonly called ports. One pressure inlet, two cylinder ports providing pressure to double acting cylinder or actuator, and one or two outlets to exhaust pressure from the cylinders

Solenoid valve failures and exclusion

When the solenoid valve is energized but does not work


Check the supply wiring is bad

connect wiring again and the connector is connect

Check whether the power supply voltage in the range of it

to the normal working range

The coil is seal off

welding again

The coil short coil short circuit

change coil

Working pressure is not appropriate

adjust the pressure different/or change 
commensurate solenoid valve

The fluid of high temperature

change commensurate solenoid valve

The impurities make main valve and moving core no work

clearing, for example, a damaged seal 
should change the seal and install filter

The liquid viscosity is too large. the frequent is 
too high and life has been came

change product


Solenoid valve can not be turn off

The main valve or iron core seal is damaged

change seal

Fluid temperature/viscosity is too high

change counterpart solenoid valve

The imparities entering the solenoid valve main valve core or iron core


Spring life has been come or deformation


The orifice and the balance hole are block



The working frequent is too high or life has been came

re-election or change product


 Other circumstance 

Internal leakage

check whether seal is damage, spring is poor assembly

External leakage


seal loose or broken/to fastening screw or change seal 

Power noise


chief fasteners loose tighten voltage fluctuation is not in 
the allowed range, adjust the voltage.the iron core suction surface haveimpurities or imbalance, please timely cleaning or change


Darhor flowmeters

Q. How are darhor flowmeters properly read?
A. The flow rate is read at the maximum width portion of the float regardless of shape.

Q. What factor is used to correct for different flowmeter inlet pressure?
A. None, if the flowmeter is exhausting to the atmosphere. If back-pressure is present due
to downstream plumbing or restrictions, use the conversion curves and formulas for gases.

Q. Why are top mounted valves recommended for flowmeters used for vacuum service?
A. To maintain atmospheric pressure in the indicating bore and therefore preserve accuracy;
an inlet restriction would reduce pressure in the bore. This is essentially the opposite situation
to outlet back-pressure in a pressure system which increases pressure in the bore and also
affects accuracy.Remember that all standard Darhor flowmeters are calibrated for standard
atmospheric pressure and temperature in the bore.

Q. Is the LZS or LZM Flowmeter compatible with any media?
A. The LZS Flowmeter is manufactured from a polycarbonate plastic and the LZM-6T Flowmeter
is manufactured from acrylic. Compatibility charts need to be reviewed to determine if these
materials of construction are compatible with your media.

Q. Are special ranges available for the LZS and/or LZM-6T Flowmeter?
A. Yes, other ranges are available which are not specified in our catalog. Please feel free to contact
Darhor with questions on these ranges.

Q. How do I make the conversion for a specific gravity different than air or water?
A. In our Application Guides for using flow products, there is a formula to make this conversion.

Q. Which flowmeters are available with NIST traceability?
A. All Darhor LZM.LZS,and Oxygen flowmeters are available with NIST traceability on all air ranges
except for GA24.VA24 Series model ,This model is Germany Standard.

Q. Is a Darhor Certificate of Conformance offered with any of the flowmeter models?
A. A standard Darhor  Certificate of Conformance can be offered with all Darhor LZM,lZS,GA24,
LZB flowmeters on all water ranges (or other compatible liquids).

Q. How will the calibration of a standard Darhor flowmeter be affected when used to measure the
flow of hydrogen?
A. The readings will be low due to the lower specific gravity of hydrogen compared to air. This error
can be corrected utilizing the conversion curves in Bulletin F-41 or in OEM quantities special
calibrations can be provided.

Q. Can the lZS be used to measure flows of liquids with entrained air bubbles or particles?
A. No, the LZS Series should be used with clear or cloudy liquids that are free from all particulates or
air which could effect the reading.

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