Home » Hydraulics Shop » Hydraulic Valves » Lock Valves

Lock Valves

Looking for help or a discount?

Call (800) 823-4937

Keep hydraulic cylinders locked in position even when pressure drops. Lock valves hold heavy loads safely in place, preventing dangerous drops if hoses burst or pumps fail.

Hydraulic Safety Lock Valves for Load Holding

Think of lock valves as parking brakes for your hydraulic cylinders. When you stop operating the controls, these valves instantly lock the cylinder in place – no drift, no creep, no unexpected movement. Even if a hose bursts or your pump quits, that load stays exactly where you left it. This fail-safe protection makes lock valves mandatory on man lifts, crane booms, and any equipment where dropping loads could hurt someone.

Our lock valves mount directly on cylinder ports or install in-line near the cylinder. They combine a pilot-operated check valve with precise pressure controls that only release when you actively command movement. Double lock valves protect both extend and retract functions. Single locks protect just the holding side. We stock valves for everything from small 5 GPM cylinders to massive 50 GPM systems.

Choose from cushioned models that prevent shock loads, adjustable types that let you set release pressure, or load-control valves that lower heavy weights smoothly. Standard SAE and NPT ports match common cylinders. Every valve includes mounting hardware and clear markings showing proper orientation – these must install correctly to work safely.

Item SKU: RD-1450

RD1450 Prince Lock Valve, 1/2" Port

RD1475 Prince Lock Valve, 3/4″ Port

$278.00

0 out of 5

0 Reviews

Why Lock Valves Are Essential Safety Equipment

Regular check valves can’t safely hold suspended loads because they leak slightly over time. Lock valves solve this with a piloted poppet design that seals absolutely tight. The pilot pressure requirement means they won’t open accidentally – you need positive pressure from your control valve to release them. This double safety (tight sealing plus pilot operation) meets OSHA and ANSI requirements for personnel lifting equipment.

Lock valves also solve the dangerous problem of runaway loads. When lowering heavy weights, the load can push fluid out faster than the pump supplies it, causing cavitation and loss of control. Lock valves meter the lowering speed, keeping it smooth and controlled regardless of weight. They prevent the jerky, unstable movement that happens when regular valves try to control overrunning loads. This matters on equipment like aerial lifts, dump bodies, and crane extensions where gravity wants to take over.

Different lock valve types serve different safety needs. Pilot-to-open checks are simplest – they lock until pilot pressure releases them. Counterbalance valves add adjustable pressure settings for smooth motion control. Overcenter valves provide the ultimate in stability, preventing any movement until commanded. Motion control valves combine multiple functions, giving you lock, cushioning, and thermal relief in one package. For hydraulic motors, brake valves lock rotation when pressure drops.

Selecting the right lock valve requires knowing your cylinder bore, rod size, and maximum pressure. Undersized valves restrict flow and slow operation. Oversized valves may not control properly. We help contractors and equipment builders choose lock valves that meet safety codes while maintaining good cycle times. Tell us what you’re lifting or holding – we’ll recommend the right valve with proper pilot ratios and pressure settings. These are safety-critical components, so we only stock quality brands that meet industry standards.

Frequently Asked Questions

1. What is a lock valve and how does it work?

A lock valve is a pilot-operated check valve that locks hydraulic cylinders in position. It blocks flow completely until receiving pilot pressure from your control valve. When you operate controls, pilot pressure opens the valve for normal movement. Release controls, and it instantly locks tight.

2. What are lock valves used for?

Lock valves provide safety holding for suspended loads on man lifts, boom trucks, forklifts, and dump trailers. They’re required by safety codes on equipment lifting people or where dropped loads could cause injury. Also used on jacks and presses for positive positioning.

3. How do I know which lock valve to choose?

You need your cylinder’s bore diameter, operating pressure, and flow rate (GPM). Choose a valve rated for your pressure with ports matching your cylinder. The pilot ratio (typically 3:1 or 4:1) determines how much pressure opens the valve. Higher ratios hold better but need more pilot pressure.

4. What’s the difference between lock valves and holding valves?

Lock valves completely prevent movement until piloted open – maximum safety for personnel lifting. Holding valves (counterbalance/overcenter valves) allow controlled movement based on load pressure – better for smooth operation but less absolute in holding. Many people use the terms interchangeably.

5. Do I need single or double lock valves?

Use single lock valves when you only need to hold against gravity (like a lift that only needs locking when raised). Use double lock valves when loads could push either direction or when codes require locking both ports. Double locks cost more but provide complete bi-directional safety.

Lock Valves

Hydraulic Safety Lock Valves for Load Holding

Quick Buy