OM VRFU90°1/4"is a unidirectional flow control valve with a 1/4"port,specifically designed as a 1/4 flow control valve for pneumatic cylinder speed regulation.Featuring a 90°swivel elbow body and an integrated check valve,it delivers adjustable metered flow in one direction and unrestricted free flow in reverse.Suited for factory automation,packaging machinery,and assembly tooling.

　　What Is a Unidirectional Flow Control Valve?

　　A unidirectional flow control valve,commonly called a one-way flow control valve,is a pneumatic component that restricts airflow in one direction while allowing full flow in the opposite direction through a parallel check valve.It is classified as a throttling valve,typically used at the exhaust port of a pneumatic cylinder to achieve smooth,adjustable piston speed without affecting the supply flow.

　　The OM VRFU90°1/4"is an in-line unidirectional flow control valve.Its 90°swivel elbow design enables direct mounting onto cylinder ports,eliminating the need for additional fittings and reducing space requirements in compact pneumatic panels.The valve body incorporates a precision needle valve for flow metering and a polymer check valve for reverse flow.

　　Key Specifications

　　Medium:Compressed air,filtered to 40µm,lubricated or non-lubricated

　　Port Size:G1/4(BSPP)–1/4 NPT version available under a different model code

　　Connection Type:Push-in instant fitting for 1/4"OD tubing(recommended tubing:polyurethane or nylon)

　　Flow Direction:Unidirectional with built-in free reverse flow check valve

　　Adjustment:Screwdriver-adjustable needle valve with locking nut

　　Maximum Operating Pressure:10 bar(145 psi)

　　Minimum Operating Pressure:0.5 bar(7 psi)

　　Ambient Temperature Range:-10°C to+60°C

　　Nominal Flow Rate at 6 bar:900 Nl/min(free flow direction,Δp=1 bar)

　　Cv(Flow Coefficient):Approx.0.35(metered direction,fully open)

　　Check Valve Cracking Pressure:<0.3 bar

　　Body Material:Nickel-plated brass

　　Knob and Lock Nut Material:Polyacetal(POM)

　　Seals:NBR(Nitrile)

　　Weight:45 g(including fitting)

　　Technical Highlights

　　90°swivel elbow design saves panel space.The rotating body permits direct cylinder port connection,eliminating the need for a separate elbow fitting and reducing the assembly footprint by up to 40%compared to straight-body valves with separate fittings.

　　Meter-out speed control provides smooth cylinder motion.By restricting exhaust flow rather than supply,the valve prevents uncontrolled actuator lunging,a key requirement for vertical loads or delicate handling.This metering method avoids the“jumping”effect common with meter-in control.

　　Integrated check valve allows unrestricted reverse flow.A built-in polymer poppet check valve opens with less than 0.3 bar differential pressure,ensuring rapid full-bore return stroke without restricting the supply air path.

　　Locking adjustment prevents tampering.The needle valve setting is secured by a knurled polyacetal lock nut,which holds the tuned flow rate after commissioning.This is critical for high-vibration environments such as stamping press tooling or conveyor divert stations.

　　Nickel-plated brass body resists corrosion.The metallic construction withstands aggressive plant atmospheres,including washdown splashes and oil mist,while maintaining dimensional stability across the operating temperature range.

　　Applications

　　Pneumatic cylinder speed control:Installed directly on cylinder exhaust ports,it adjusts the extension or retraction speed of pneumatic actuators from 5 mm/s to full speed.Typical adjustment reduces cycle time variability to±3%in pick-and-place systems.

　　Clamping and pressing tooling:Provides slow advance and fast retract motion for pneumatic clamps and presses.The free reverse flow enables rapid opening,saving up to 0.5 seconds per cycle compared to bidirectional flow restriction.

　　Conveyor stop and divert mechanisms:Controls actuation speed of pneumatic stops and diverters,preventing product damage from impact.The 1/4"port supports tubing runs up to 3 meters without significant pressure loss.

　　Packaging machinery:Regulates actuator speed in carton folding,label application,and sealing operations.Compact body dimensions allow mounting in close proximity to cylinders inside confined machine frames.

　　Mobile pneumatic circuits:Vibration-resistant locking design and NBR seals maintain settings in portable pneumatic tools and jigs.Operating temperature range supports both cold storage areas and near-oven installations.

　　Selection Guidance

　　Suitable applications:

　　Exhaust flow control on double-acting pneumatic cylinders where smooth,adjustable speed in one direction is required

　　Installations with limited space at cylinder ports—the 90°swivel body eliminates an additional elbow fitting

　　General industrial compressed air systems operating between 0.5 and 10 bar with filtered air supply

　　Not recommended for:

　　Bidirectional independent speed control.For independent adjustment of both extend and retract speeds,use two valves or a dual flow control valve such as the OM VRFU series in a manifold configuration.

　　Vacuum applications.The valve's NBR seals and check valve design are optimised for positive pressure pneumatics;vacuum service requires a dedicated vacuum flow control valve.

　　Fluid media other than compressed air.This valve is designed exclusively for pneumatic service and must not be used for hydraulic fluids,water,or chemicals.For hydraulic flow control,select a valve rated for the required pressure class.

　　FAQ

　　1.What are the dimensions,port size,and weight of the OM VRFU90°1/4"unidirectional flow control valve?

　　The valve features a G1/4(BSPP)threaded port with a push-in fitting for 1/4"OD tubing.Overall length is approximately 43 mm,width 24 mm,and weight 45 g including the integral push-in fitting.For NPT port specification,request the equivalent NPT model when ordering.

　　2.What is the delivery time or lead time for the OM VRFU90°1/4"?

　　Standard manufacturer lead time is 2 to 3 weeks.Beijing Zhongping Technology maintains local stock of the G1/4 version and dispatches within 1 business day for in-stock quantities.Large volume orders may require factory allocation.

　　3.Is the OM VRFU90°1/4"in stock and available for immediate shipment?

　　We hold inventory of the OM VRFU90°1/4"at Beijing Zhongping Technology.Common variants are typically in stock with quantities available for same-day dispatch when ordered before 14:00 local time.

　　4.How much does the OM VRFU90°1/4"cost,and do you offer volume pricing?

　　The OM VRFU90°1/4"typically ranges from 12to18 USD per unit depending on order quantity.Volume discounts apply for orders above 100 pieces.Prices fluctuate due to exchange rates,tariffs,and factory adjustments.For an accurate quotation,contact Beijing Zhongping Technology directly.

　　5.What payment terms and methods do you accept for purchasing the OM VRFU90°1/4"?

　　We accept bank wire transfer(T/T),major credit cards,and PayPal for transactions under$5,000.For corporate customers with approved credit,Beijing Zhongping Technology offers net 30 payment terms.

　　6.How do I adjust and lock the flow setting on this valve?

　　Turn the slotted brass needle screw clockwise to reduce flow,counter-clockwise to increase.Once the desired cylinder speed is reached,tighten the polyacetal locking nut by hand to secure the setting.A 0.5 mm pitch thread provides fine flow resolution.

　　7.What is the maximum operating pressure and compatible tubing for the OM VRFU90°1/4"?

　　Maximum operating pressure is 10 bar(145 psi).The push-in fitting accepts 1/4"OD polyurethane or nylon tubing with a hardness range of Shore A 95 to 98.Ensure tubing is cut square with no burrs for reliable sealing.

　　8.What is the return policy and warranty period for the OM VRFU90°1/4"?

　　We provide a 2-year warranty against manufacturing defects.Returns require prior authorization and are accepted within 30 days for unused products in original packaging.Beijing Zhongping Technology processes RMA requests within 24 business hours.

　　9.What is the duty,customs,and HS code for importing the OM VRFU90°1/4"?

　　The HS code is 8481.30.90(check valves and other non-return valves).International shipments are dispatched under Incoterms CPT with duties and import taxes payable by the buyer.We provide commercial invoices and certificate of origin for customs clearance.

　　10.How is the OM VRFU90°1/4"installed,and can it be mounted directly on a cylinder?

　　The G1/4 male thread screws directly into a cylinder’s exhaust port.The 90°swivel body can be rotated 360°before tightening the lock nut,allowing tubing routing in any direction.No additional bracket or fitting is needed—tighten only the hex nut behind the threaded port;do not rotate the entire valve body.