723-46-43400 723-46-42800 Excavator PC200-7 PC200-8 PC220-7 PC220-8 PC300-7 Pressure Relief Valve Pressure Compensation Valve

723-46-43400 723-46-42800 Excavator PC200-7 PC200-8 PC220-7 PC220-8 PC300-7 Pressure Relief Valve Pressure Compensation Valve

Product Description

The GVO excavator relief valve, compatible with Hitachi excavators, is a key pressure control valve in the hydraulic system. It regulates hydraulic pressure, releases overload pressure, protects core hydraulic components such as the main valve and hydraulic pump, and ensures stable operation of the entire machine.

This relief valve is precision-machined from high-quality steel and undergoes overall quenching treatment. Equipped with oil-resistant and high-pressure-resistant seals, it boasts excellent sealing performance, impact resistance, and wear resistance. Suitable for the high-pressure hydraulic conditions of excavators, it effectively prevents internal leakage, pressure loss, operational instability, and vibration.

Product Introduction

This GVO cartridge-style main relief valve is a critical pressure safety component designed for the hydraulic systems of Komatsu’s flagship excavator models, including the PC200-7, PC200-8, PC220-7, PC220-8, and PC300-7. Installed within the main control valve body, it performs essential functions such as limiting maximum system pressure, providing instantaneous pressure relief during overloads, and maintaining constant load pressure. It directly determines the machine's breakout force and the smoothness of simultaneous operations, while offering ultimate overload protection for expensive hydraulic components like the main pump, cylinders, travel motors, and high-pressure lines.

The product is manufactured through precise reverse engineering based on the original valve cavity structure. Key specifications—such as total body length, the layout of upper oil ports, multi-stage seal groove positions, external thread pitch and profile, and the bottom hex-locking dimensions—fully match OEM parameters. Installation is non-destructive and straightforward; the valve can be screwed directly into place without the need for destructive modifications to the control valve bore, such as reaming, tapping, grinding, or sleeving. It is perfectly compatible with the oil circuit feedback logic of various valve assemblies, including the older direct-injection PC200-7 control valves, the electronically controlled PC200-8 valves, the reinforced PC220 series (20-ton class) valves, and the heavy-duty PC300-7 valves.

The valve body is machined from a solid bar of high-hardness alloy structural steel using CNC lathes. The spool and seat sealing interface undergo three strengthening processes: high-frequency surface hardening, low-temperature stress-relief tempering, and ultra-precision mirror-finish bore honing. This significantly increases surface hardness, enabling the valve to withstand the high-speed erosion, abrasive wear from solid particles, and high-frequency peak pressure shocks associated with contaminated hydraulic fluid in mining, quarrying, and earthmoving environments. By addressing these issues at the hardware level, the valve eliminates recurring failures such as spool scoring, seal leakage, and pressure loss due to internal leakage, establishing a stable and reliable hydraulic safety barrier for Komatsu excavators in the 20- to 30-ton class.

Packaging & Shipping

We use high-strength, environmentally friendly paper export packaging, which is reinforced, cushioned, and moisture-proof, suitable for long-distance international logistics transportation, and meets cross-border freight and environmental protection standards. International transportation adopts formal cross-border logistics, with full tracking of logistics information and supporting customs clearance documents to ensure smooth customs clearance and timely delivery of goods overseas.

Company Introduction

The GVO brand is a manufacturer of hydraulic components. We mainly produce the most comprehensive range of pilot pumps, gear pumps, relief valves, hydraulic pumps, electrical components, hydraulic parts, engine assemblies, traveling assemblies, rotating assemblies, distribution valves, and other components.

We are factory direct sellers without any middlemen profiting from price differences. The quality is definitely the best for you because we are the ones who produce them. We cannot tarnish our reputation. The prices are also the most favorable for you. There is a stable delivery speed.

We value every customer and provide you with the best service. We offer pre-sale, in-sale, and after-sale guarantees. Any problems will definitely be resolved for you. We are always available to serve you.