Model BKS/DPM22-32, Direct Acting Low Pressure Cartridge Relief Valve now available in 0-16 (232 psi) adjustment range

One of the most often asked questions from the field is how low can our direct operated pressure relief valves be adjusted to? Accurate and reliable lowest possible pressure adjustment, along with acceptable flow rates, is often critical for pilot control of larger DIN and Spool Type control valves, and on pressure compensated pump and fluid motor

Data sheet 2.1-542 shows the adjustment graphs and dimensions on the standard cartridge, note the following features:
1.    Extremely low internal leakage below cracking (setting) pressures.
2.    Adjustment pressure vs. flow rate graphs on both high and low adjustment ranges.
3.    Nominal pressure adjustment graph showing adjusting screw turns required for specific pressure setting.
4.    For lowest pressure adjustment range 0 – 232 psi, please contact us with application details.
 

CATALOG SECTION 1.10 –EXPLOSION PROOF PROPORTIONAL SOLENOID OPERATED DIRECTIONAL CONTROL VALVE

Direct Operated Spool Type, in NG6 (DO3) Size, with explosion-proof rated proportional solenoids; 4-way, 3 position, closed center or 4 way two position.

For the latest Data Sheet No. 1.10-87E. This is our Model WDCBFA06-ACB-S-G24/L115, NG6 (DO3) sized proportional directional control valve, 4 way 3 positions, double solenoid, rated to 25 liters per minute and 5000 psi.  Competitively priced, delivery can be made in 4 – 5 weeks ARO.

The proportional explosion proof solenoids used are Type Exd 11c and approved for use in Zones 1 and 2, Gas Groups A, B, C, per EN Norm / ATEX 1023 standards, also IECEx, and Gost Standards. They are not UL or CSA listed, but are now usually accepted in the US & Canada when the UL/CSA seal is not a mandatory requirement.  They are universally accepted elsewhere in the world, and are the standard applied for most off shore drilling platform requirements. 

The solenoids meet IP-67 water exposure protection class, have both a 15 or 9 watt power rating, and maximum spool stroke requires 610 milliamps at 5000 psi, to achieve 25 liter/min flow rate.  Delta P at 25 liter/min is 10 bar (with 140 SUS fluid). For additional construction information and dimensions, see data pages 1.10-75E. Note that rated flow is reduced from the standard non-explosion proof NG6 size proportional valve.  Note also that a spacer plate is required between the valve body and the DO3 sub- plate to account for explosion proof solenoid overlap.  More detail on the proportional solenoid used is shown on data page 1.1-183E in the 1.1 solenoid section. If viton seals are required, add “D1” to end of model number.

These valves are often applied in the oil extraction and refining industry, on off shore drilling operations, on underground mining and tunneling machinery, in pipeline pumping stations, on compressed gas delivery systems, and in petro-chemical operations.

New Data Pages for NG6 Size Solenoid Operated Directional Control Valve (Sub-plate mounted, NFPA-03, interchangeable)

Please click on Data page 1.2-59E for our NG6 sized model (flow rate to 21 GPM, pressures to 5100 psi) NFPA sub-plate mounted (D03). This model is now offered with the popular mobile equipment type “Slip-on Solenoid“ option as well as with the standard ISO bolt on solenoid assembly.  Additionally, and of major importance, nominal internal leakage curves are now printed and shown on page 3.  We offer lowest internal leakage as a standard, and can quote on special option „extra-tite“ internal leakage.

In an always tough competitive market, we still maintain and increase our sales of this type and size of direct solenoid operated directional control valve.  This is due to the extra options and functions this valve offers the users that include some major OEM and off-the highway equipment manufacturers.

Ed V. Askey

Oil Pilot Operated Poppet Valves are available from Wandfluh

Although no longer included in the Standard Catalog, high pressure, virtual zero leak, oil pilot operated poppet valves are still offered by Wandfluh.  Available in NG4, NG6, and NG10-NFPA sub-plate mount sizes, with pressure rating to 5000 psi, and flow rating to 21 GPM, this series offers the same operating features as the solenoid operated and air pilot operated poppet valve series. Options such as corrosion resistant coatings or materials, manual over rides, and seal materials, are also available.  See data page 1.11-7140E on the NG6 (D03) size for details and dimensions.  NG4 and NG10 pages are also readily available on our website.  Please call our office for a standard list price. 
Oil pilot operated poppet valves offer many desirable design features, ideal for certain applications such as:
1.  Sequencing Circuits:  pilot pressure will shift valve fully (to open or to close) at any psi signal that is within the catalog pressure range selected.
2.  Where remote pilot control is required, or in hard to fit locations, and where electricity or pneumatic pressure is not available,. (e.g. underground mining)
3.  Where fail safe on loss of power or signal is required.  i.e. poppet valve shuts or opens on loss of pilot signal or loss of main system pressure.
4.  Stored Hydraulic Power Banks, such as accumulators to power Diesels or Turbines for cold start-up, or on remotely located pipeline valves, or to power portable hydraulic rescue tools.
5.  For piloting larger DIN type logic valves or spool valves and virtual zero leak pilot valves are required.
6.  Where different fluids, or fluid conditions are required for pilot fluid & main system fluid.  E.G. separate reservoirs for hot and cooler fluids.

A major application advantage is that the Wandfluh oil pilot operated poppet valves allow selection of a model that will handle the available pilot pressure the system has on hand.  This is, the user does not have to add external valving or a special option to accept the available pilot pressure. He can select the model that is compatible with the pilot pressure he has! See pages 2 & 3 of data page 1.11.7140E. Min-Max curves for a variety of pilot pressures versus system pressure are shown on page 2, Dimensions for each type shown on page 3.

Ed V. Askey

2.6. Proportional Throttle Valve, Drop-in Cartridge Style. 42 GPM Flow Rate

For many years Wandfluh has offered a Proportional Throttle Valve in DIN 25 drop-in cartridge style, Model EDR2500-160-G24.  It is rated to provide accurate flow rate adjustment from 20 cubic inches per minute to 42 GPM, and pressures to 4500 psi.. This cartridge fits in an ISO 7368/DIN 24342 cavity, or we can provide it installed in a 2-port high strength aluminum housing with either!’’ NPT or SAE-16 threaded ports.  This housing model number is K25-100-NPT or SAE St.thd.  See data page 1.12-505E.
             
This unit uses a 60mm proportional solenoid, available in 12 or 24 VDC, it includes a push type manual over ride, and is enclosed in a flange mount zinc plated steel solenoid housing.  It is available with a selection of electrical connectors including the standard DIN 43650 style.  Standard Wandfluh amplifiers and companion electronics can be used to drive the solenoid.

The unique Wandfluh pressure balanced metering spool allows a direct solenoid operated design which assures accurate, smooth and fast response to a signal change.  A special data page, # 2.6-1014 and operating graphs are available on request from the Wandfluh, Mundelein IL office.

Typical applications for this valve include variable speed control of fluid motor driven conveyors, lowering speed control of weight loaded hydraulic presses,  variable speed control of fluid motor driven water pumps and boosters,  fluid transfer systems, and mobile equipment fan drive systems.

Ed V. Askey

Successful but often overlooked Wandfluh Poppet Valve Applications

1.     Refer to data sheet 1.11.2140E.  The typical 3 way, two position control circuits utilize virtual zero leak Wandfluh solenoid operated poppet valves for load lift, hold, and lower functions, but the user still must provide means to dump or shut-off the fixed displacement pump providing pressure and flow. Else, power will be wanted, heat will be generated, and at least 2 more components, plus fittings and piping must be added to the manifold control station.  Wandfluh offers a fourth function as part of the system and housing by also installing another 3 way solenoid valve which (see model A3406 under “Symbols” on page 1)., when signaled can both dump the pump flow to tank and also unload any pressure remaining in the cylinder and piping.  At the rest position (all power to solenoids off), all three ports are locked thus also holding a loaded cylinder in a virtual zero drift position, regardless of any undue forces on the cylinder load. A further benefit is that a “float position is created for cylinder and its load (such as needed by small snowplows or road scrapers.). This model is also offered in the NG4 and NG10 valve sizes.

2.    Refer to data sheet 1.11-2150E. Here we offer a poppet style 4 way 3 position, double solenoid operated directional control valve that will hold all ports virtual zero leak when in the no power (neutral) situation (each port is blocked virtual zero leak.). This is often a requirement in the test bench and fixture clamp markets, as well as on certain positioning loaders/transporters, and in any designed machine that requires both safety when holding a load and fail-safe shut-off of actuators when signaled. 

NEW PRODUCT – Solenoid operated, two way normally closed / normally open shut-off valve that is cavity interchangeable

Wandfluh now offers a solenoid operated, two way normally closed / normally open shut-off valve that is cavity interchangeable with the common U.S. cartridge valve manufacturers’ SC-08-20 screw-in style cartridge with the US standard ¾” -16 UNF Cavity Thread. See data sheet 1.11-2083E. For years this model was used in million quantities by many major US farm and construction equipment manufacturers on tail gate lifts, snow plows, platform lifts, small hydraulic cranes, manlifts, forklifts, pallet stackers and many other applications.  We now receive inquiries from many of our distributors and OEM customers as to its availability from Wandfluh, either to service their customers, or for use in new low flow rate applications where small and virtual zero leak shut-off valves are required, and smaller use quantity orders are asked for and readily available.

In addition to reliable quality and delivery, the Wandfluh model offers higher pressure ratings, and flow rates with some desirable options such as push type manual over ride, mobile equipment type slip-on solenoids offered in a variety of solenoid voltages and electrical connectors, and selection of seal materials.  Free reverse flow when de-energized, virtual zero leak when holding pressure.  Rated to 5000 psi continuous duty at 10GPM (see performance characteristics pg 2). At current known order quantities we cannot match high order quantity pricing, but offer a high quality substitute when this size and type valve is needed in manifolds and systems to enhance performance, or when other sources are not available.

Proportional Solenoid Operated, 3-Way Flow Control Cartridges

New emphasis on more efficient fluid motor driven fan drive systems requires accurate and repeatable proportional solenoid driven 3 way flow control valves, both the direct operated throttle type and the pressure compensated type, this again gives us opportunity for our 3 way screw-in cartridge valves shown in catalog section 2.6. (An example is page 2.6-665E) We can now offer the 3 way direct operated pressure compensated flow control valves, (once termed “Priority Flow Control Valves”) to a variety of mobile equipment manufacturers and users for the control of fluid motor drive circuits that need a high degree of precision and accurate response to feedback signals, over millions of cycles. Our offerings can be fitted with mobile equipment slip-on solenoids, explosion proof solenoids, viton seals, corrosion resistant plating, and other customer requested options, and the necessary electronic amplifiers to control the fan drive system can be supplied with the amplifiers installed in the proportional solenoid, or for external installation.  Valves are offered in 2 sizes, 22mm and 33mm threads, and a 42mm size is now in final design.

For more complete product information see catalog data pages 2.6-666E, 2.6-667E, 2.6-645E, 2.6-646E, and electronic amplifier pages 1.13-75E, 1.13-240E.

2.6 Proportional Throttle Valve, Drop-in Cartridge Style. 42 GPM Flow Rate

For many years Wandfluh has offered a Proportional Throttle Valve in DIN 25 drop-in cartridge style, Model EDR2500-160-G24. It is rated to provide accurate flow rate adjustment from 20 cubic inches per minute to 42 GPM, and pressures to 4500 psi.  This cartridge fits in an ISO 7368/DIN 24342 cavity, or we can provide it installed in a 2-port high strength aluminium housing with either NPT or SAE-16 threaded ports.  This housing model number is K25-100-NPT or SAE St.thd.  See data page 1.12-505E in the general catalog or online.

This unit uses a 60mm proportional solenoid, available in 12 or 24 VDC, it includes a push type manual over ride, and is enclosed in a flange mount zinc plated steel solenoid housing.  It is available with a selection of electrical connectors including the standard DIN 43650 style.  Stand Wandfluh amplifiers and companion electronics can be used to drive the solenoid. 

The unique Wandfluh pressure balanced metering spool allows a direct solenoid operated design which assures accurate, smooth and fast response to a signal change.  A special data page, 2.6-114 (2 sides) and operating graphs are available on request from the Wandfluh, Mundelein, IL office.

Typical applications for this valve include variable speed control of fluid motor driven conveyors, lowing speed control of weight loaded hydraulic presses, variable speed control of fluid motor driven water pumps and boosters, fluid transfer systems, and mobile equipment fan drive systems.

Ed V. Askey

Accumulator or High Flow Pump Unloading Valve, with Dual Unloading/Reloading Pressure Adjustments

This Unique pressure control valve was developed in Western Europe where power costs are much higher and there is considerably more emphasis placed on efficient hydraulic systems that save power.  Thus, accumulators and high/low pump power units are more often required. Data sheet: 2.1-950E, and 2.1-970E

The main feature of the Wandfluh Accumulator or Pump Unloading Valve is that it offers adjustable pressure control for both the unloading (dump pump flow to Tank) and reloading (rebuild system pressure) functions.  Most unloading valve circuits offer only an unloading pressure adjustment and a fixed not readily adjustable reloading pressure.  The difference between the unloading and reloading pressure is example, typical unload-reload ratio for clamping circuits (hold at high pressure) is 90%; an example would be unload at 1000psi, reload at 900psi, but this is an uncommonly high ratio for many pressure holding circuits, and not practical for fast approach slow feed circuits where there is time to make up stored low pressure volume at low power input, or demand for holding pressure is sporadic and used only for emergencies.  Only one Wandfluh dual Adjustment Unloading valve is required for a wide variety of accumulator pressure control applications, and the desired unload-reload ratio can be re adjusted in the field if unload-reload requirements change.

Other important features are:
1.  Internal spook leakage is extremely low (see page 2 of data page) and thus do net bleed down the charged accumulator quickly and the pressure or charging pump does not have to operate often.
2.  The valve comes in 2 sizes, NG6 (NFPA D03) and NG10 (NFPA d05, and mounts on standard NFPA sub-plates.
3.  The NG6 size can used to pilot larger DIN type poppet vlaves that may require a variety of pilot pressures and flow rates depending on the ratio choices of different sizes of DIN poppet valves. 
4.  Both sizes are rated continuous duty to 5000 psi, peak to 5800 psi. 
5.  All working parts are of steel, sub-plates can be provided in steel or high grade aluminum, pressure adjustment valves have lock nuts; for fine resolution, 3 pressure adjustment ranges are offered as standard, seals are Buna N, or Viton; EP (ethelene propalene) on special quote.
6.  If valves are to be exposed to wet, humid, icy conditions, or salt water, ask us for quotation on CRES surface finishes or Type 316 L stainless steel external parts.

Ed V. Askey