723-50-53102 723-50-53101 Boom Locking Valve Boom Holding Valve PC120-6 PC130-6

Product Specification

723-50-53102 723-50-53101 Boom Locking Valve Boom Holding Valve PC120-6 PC130-6 PC120-7 PC130-7 PC120-8 Excavator Parts

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 plate-mounted main relief valve is a universal hydraulic mainstay for Komatsu's classic 12-13 ton small and medium-sized excavators. It is compatible with the older 6th generation PC120-6 and PC130-6 negative flow models, the PC120-7 and PC130-7 direct injection 7th generation models, and the upgraded PC120-8 electronically controlled 8th generation model. It is a core safety pressure regulating component on the main control valve, controlling the highest pressure of the entire machine system. It is also a popular and versatile spare part for repairing and replacing the hydraulic systems of three generations of classic Komatsu models.

The valve body is precision cast in one piece from high-strength, high-toughness ductile iron. The internal oil flow channels are integrally formed using a lost-wax casting process. The valve body has a uniform and dense wall thickness, eliminating fatal defects such as sand holes, air holes, internal porosity, high-pressure cracking, and internal oil leakage that are common in ordinary rough castings. It can withstand high-frequency, high-pressure pulse impacts from the hydraulic system for a long time, and the valve body structure has extremely high stability.

The internal core valve core, valve seat, pressure regulating spring, and damping throttling components are all made of high-grade alloy structural steel. They undergo three core heat treatment and precision machining processes: carburizing and quenching hardening, low-temperature stress-relieving tempering, and high-precision internal and external cylindrical grinding. The surface finish of the valve core mating surfaces reaches the micron-level standard for hydraulic precision valves, ensuring smooth reciprocating opening and closing without jamming or sticking. This significantly reduces common faults caused by long-term erosion of high-pressure hydraulic oil, such as scratches on the sealing surface, increased clearance, and excessive internal leakage.

The valve body exterior undergoes a blackening and passivation rust-proofing treatment, while the internal oil passages are treated with phosphate for corrosion and rust prevention. Facing harsh operating conditions such as splashing mud and water on construction sites, long-term outdoor storage with moisture and oxidation, and continuous corrosion from high-temperature hydraulic oil, the valve is less prone to rust and clogging of the throttling orifice, ensuring unobstructed oil flow and valve stability over long-term use.

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.