VHP51-400 | 5800 PSI Nickel-Plated High-Pressure Unloader Valve

Overview

• The Annovi Reverberi VHP51-400 is a nickel-plated unloader valve designed
  for high-pressure cleaning systems that demand extreme durability and reliable pump protection.
• Rated up to 5,800 PSI (≈400 BAR), it is engineered for contractors,
  facility operators, and industrial users working in the toughest environments.
• Provides consistent system regulation while protecting critical components from harmful
  overpressure conditions and pressure spikes.
• Ideal for high-demand systems where long service life, safety, and uptime are top priorities.

Built for Extreme Durability

• Features a nickel-plated housing that adds a protective layer over the base
  metal for enhanced corrosion and wear resistance.
• Outperforms standard brass valves in environments exposed to water, chemicals, salt, and
  abrasive debris.
• Nickel plating helps prevent corrosion, pitting, and surface degradation over long service
  intervals.
• Especially well-suited for systems that cycle frequently throughout the day under harsh
  conditions.
• Delivers a strong balance of durability and protection for chemically aggressive or outdoor
  environments.

High-Pressure Performance – 5,800 PSI

• Rated for 5,800 PSI (≈400 BAR), supporting extreme-duty cleaning systems.
• Provides consistent bypass function, automatically redirecting water when
  spray flow is interrupted.
• Maintains stable pressure control to prevent dangerous spikes and shock loads
  on pumps, hoses, and fittings.
• Offers reliable protection during continuous high-pressure operation, minimizing risk of
  pressure-related failures.
• Supports uninterrupted performance in applications where downtime is costly.

Seamless System Integration

• Equipped with 1/2″ F threaded connections for easy installation into
  commercial and industrial rigs.
• Universal-style fit allows straightforward upgrades or replacements without major plumbing
  changes.
• Compatible with a wide range of pressure washer systems, from portable rigs to stationary
  wash bays.
• Compact design simplifies integration into tight equipment layouts while maintaining service
  accessibility.

Protecting Pumps & Extending Service Life

• Automatically diverts water into bypass mode whenever the spray trigger is
  released.
• Reduces system strain and prevents overpressure damage to pumps, seals, pistons, and bearings.
• Helps maintain pump integrity over time, especially in continuous-duty or frequent start/stop
  applications.
• Contributes to extended pump life, reduced maintenance intervals, and lower
  repair costs.
• Supports more consistent daily operation and overall system reliability.

Operator & System Benefits

• Corrosion-resistant nickel-plated housing withstands harsh chemicals,
  moisture, and outdoor exposure.
• High-pressure rating (5,800 PSI) makes it suitable for extreme-duty cleaning
  systems.
• Automatic bypass operation enhances operator safety and protects equipment
  during idle and trigger-release periods.
• 1/2″ F connections provide secure fit and broad compatibility with
  professional rigs.
• Reliable pressure regulation reduces the risk of pump failure, unplanned downtime, and costly
  repairs.

Typical Applications

• Chemical Wash Systems: Handles corrosive detergents and aggressive cleaning
  agents.
• Marine Cleaning: Resists saltwater corrosion in shipyards, docks, and
  offshore environments.
• Industrial Facilities: Operates reliably in manufacturing and processing
  plants with continuous cleaning demands.
• Contractor Operations: Long-term reliability for high-pressure mobile
  cleaning rigs.
• Outdoor Wash Stations: Performs consistently in locations exposed to weather,
  moisture, and debris.

Key Features & Specs

• Model: VHP51-400
• Pressure Rating: 5,800 PSI (≈400 BAR)
• Construction: Nickel-plated housing for corrosion resistance and durability
• Connections: 1/2″ F threaded ports for secure installation
• Function: Automatic bypass protection to prevent overpressure and protect pumps
• Applications: Chemical wash systems, marine cleaning, industrial plants,
  contractor rigs, outdoor wash stations