310-0394 352-7113 352-7116 352-7117 Main Relief Valve Pressure Relief Valve

Product Specification

310-0394 352-7113 352-7116 352-7117 Main Relief Valve Pressure Relief Valve Safety Valve E320D 324D 329D 330D 336D 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 GVO cartridge-type main relief valve is a dedicated distribution valve and main pressure protection valve for classic D-series direct injection engines in medium and large heavy-duty excavators. It is perfectly compatible with five benchmark models with extremely large market presence: E320D, E324D, E329D, E330D, and E336D. It is a 1:1 replica of the original , measuring the orifice diameter, thread pitch, cartridge stroke, internal valve core structure, and pressure regulation parameters. The valve positions are directly interchangeable across the five models, making it an indispensable and ultimate overload relief safety barrier for D-series hydraulic systems.

The entire valve body is forged from a high-grade alloy structural steel blank, completely eliminating the inherent defects of inferior aftermarket cast iron valve bodies, such as easy cracking under high pressure, slight deformation under long-term reciprocating pressure, and easy erosion damage to the sealing surface by high-speed hydraulic oil.

The valve core, valve sleeve, and valve body—all core pressure-bearing components—undergo three high-precision machining processes: full-size precision turning on a CNC lathe, high-precision centerless grinding of the outer diameter, and diamond honing of the valve sleeve inner bore. The clearance between the valve core and valve sleeve is controlled within micron-level ultra-precision tolerances, minimizing internal oil leakage under high pressure. This fundamentally eliminates common industry problems such as pressure regulation drift, unstable locking, and weak or ineffective pressure relief under heavy loads.

All pressure-bearing components undergo a dual strengthening treatment: tempering heat treatment followed by surface carburizing and quenching. This results in uniform overall hardness of the valve body, maximizing resistance to high-frequency hydraulic shock and fatigue creep. It can withstand tens of thousands of reciprocating opening and closing pressure shocks at 35MPa without experiencing valve core jamming, external thread stripping under stress, or permanent deformation of the sealing ring mounting groove.

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.