723-40-87500 Return Oil Back Pressure Valve Hydraulic Valve PC200-7 PC300-7

Product Specification

723-40-87500 Return Oil Back Pressure Valve Hydraulic Valve PC200-7 PC300-7 PC400-7 PC300-8 PC400-8 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 flange-mounted main relief valve is the core pressure control valve for the hydraulic system of Komatsu's classic large-tonnage excavators. It is generationally compatible with the PC200-7, PC300-7, and PC400-7 direct-injection 7th generation models and the PC300-8 and PC400-8 electronically controlled injection 8th generation models, covering mainstream heavy-duty excavators in the 20-ton, 30-ton, and 40-ton classes. As the main control and distribution valve, it fully manages the highest working pressure of the entire machine's negative flow hydraulic system. It is a key precision hydraulic component that determines the explosive power of heavy-duty excavation, the stability of the machine's operation, and the service life of hydraulic components.

The valve body is precision cast in one piece using high-strength, high-toughness alloy ductile iron. The internal oil flow channels are integrally formed using lost-wax precision casting. The valve body has a uniform and dense wall thickness, eliminating fatal defects such as sand holes, porosity, internal looseness, high-pressure impact cracking, and internal oil leakage common in ordinary rough castings. It can withstand the high-frequency, high-pressure pulse impacts of hydraulic systems under mining conditions for extended periods, maximizing the pressure-bearing stability of the shell.

The internal core valve core, valve seat, pressure regulating spring, and damping throttling components are all made of high-quality alloy structural steel. They undergo three core 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 reaches the micron-level standard for precision hydraulic valves. The reciprocating opening and closing damping is uniform, without jamming or stuttering, greatly reducing common failures such as sealing surface scratches, increased clearances, and excessive internal leakage caused by long-term high-pressure hydraulic oil erosion. The valve body is treated with blackening and passivation for rust prevention, and the internal oil passages are treated with phosphate for corrosion and rust prevention. It is not prone to rust and blockage of the throttling orifice in harsh environments such as impact from mining gravel, soaking in mud and water, large temperature differences between day and night, and continuous corrosion from high-temperature hydraulic oil. It ensures smooth oil passages and prevents valve jamming during 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.