723-40-91500 723-90-66900 Excavator PC200-7 PC200-8 PC220-7 PC300-7 PC350-7 Main Pressure Relief Valve Action Control Valve

723-40-91500 723-90-66900 Excavator PC200-7 PC200-8 PC220-7 PC300-7 PC350-7 Main Pressure Relief Valve Action Control 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 core excavator models (PC200-7, PC200-8, PC220-7, PC300-7, and PC350-7). It plays a pivotal role in limiting circuit pressure, relieving overloads, and stabilizing load pressure; its performance directly determines the excavator's digging force, operational coordination, and the service life of major hydraulic components.

Precision-engineered to match Komatsu’s original multi-way valve cavity specifications, this product aligns perfectly with parameters such as insertion depth, external thread pitch, radial oil port positioning, seal groove dimensions, and the hex-locking structure. Installation is non-destructive—simply screw the valve into the block and tighten it—eliminating the need for invasive modifications like reaming, tapping, or grinding the main control valve bore. It is fully compatible with the hydraulic control logic of various valve assemblies, including the older direct-injection distribution valves (PC200-7), electronically controlled upgraded main control valves (PC200-8), reinforced 20-ton class valve groups (PC220-7), and heavy-duty multi-way valves for large-tonnage models (PC300-7, PC350-7).

The valve body is CNC-machined from a single piece of high-hardness alloy steel bar stock. The sealing surfaces of the spool and seat undergo a triple-hardening process—high-frequency quenching, low-temperature tempering, and ultra-precision bore honing—significantly enhancing wear resistance. This ensures long-term durability against the high-speed flow, abrasive particles, and high-frequency pressure spikes often found in hydraulic fluid contaminated by impurities in mining, quarrying, and earthmoving operations. By preventing issues such as spool scoring, seat seal failure, and persistent internal leakage at the source, this valve establishes a robust safety foundation for Komatsu’s core 20-to-35-ton excavator models.

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.