Part Number: 7657
Category: Pressure Washer Accessories → Spray Nozzles → High-Pressure Spray Nozzles
Type: PNR 1/4" MNPT 40° 4.5 Stainless Steel Spray Nozzle – Pressure Washer Replacement Nozzle

The PNR Stainless Steel Spray Nozzle (Part #7657) is a genuine OEM high-pressure replacement nozzle designed for commercial, industrial, agricultural, and residential pressure washing applications. Featuring a 40-degree fan spray pattern and a 4.5 orifice, this nozzle provides broad, even water distribution for efficient rinsing, washing, and general-purpose cleaning while maintaining consistent operating pressure.

Key Features & Benefits

• Genuine PNR OEM high-pressure spray nozzle
• Part Number: 7657
• Wide 40° fan spray pattern
• 4.5 orifice size
• 1/4" MNPT connection
• Manufactured from AISI 416 stainless steel
• Precision-machined for consistent spray performance
• Corrosion and wear resistant
• Excellent for rinsing and general-purpose cleaning
• Broad surface coverage for improved cleaning efficiency
• OEM-quality construction for long service life

Technical Specifications

Part Number: 7657

Manufacturer: PNR

Product Type: High-Pressure Spray Nozzle

Thread Size: 1/4" MNPT

Spray Pattern: 40°

Orifice Size: 4.5

Nozzle Size: 4.5

Material: AISI 416 Stainless Steel

OEM Replacement: Yes

Compatible Applications

Suitable for use with:

• Pressure washer spray guns
• Pressure washer spray wands
• Pressure washer lances
• Commercial pressure washers
• Industrial cleaning equipment
• Vehicle washing
• Fleet washing
• Building exterior cleaning
• Agricultural equipment cleaning
• General-purpose pressure washing

Always verify the thread size, nozzle size, operating pressure, and machine flow requirements before ordering.

Function of the Spray Nozzle

The PNR 7657 spray nozzle helps:

• Produce a wide 40° high-pressure fan spray
• Deliver even water distribution across large surfaces
• Remove dirt, dust, mud, and loose debris efficiently
• Maintain consistent operating pressure and water flow
• Improve cleaning efficiency for routine washing and rinsing applications

Its 40° spray pattern provides broad coverage with moderate cleaning force, making it an excellent choice for general-purpose cleaning where efficient surface coverage is important.

Common Signs Replacement Is Needed

Replace the nozzle if you notice:

• Uneven or distorted spray pattern
• Reduced cleaning pressure
• Worn or enlarged orifice
• Clogged nozzle
• Damaged threads
• Corrosion or physical damage
• Increased water consumption caused by nozzle wear

Replacing a worn nozzle restores proper spray pattern, operating pressure, and cleaning efficiency.

Installation & Service Notes

• Turn off the pressure washer and relieve system pressure before replacing the nozzle.
• Verify compatibility with the 1/4" MNPT connection and 4.5 orifice size.
• Install the nozzle securely without overtightening the stainless steel threads.
• Inspect the nozzle seat and threads for debris before installation.
• Test the spray pattern after installation to verify proper operation.
• Replace the nozzle if wear causes pressure loss or an inconsistent spray pattern.

Important: Match the 4.5 orifice size to your pressure washer's GPM and PSI specifications to maintain proper operating pressure and cleaning performance. The 40° spray pattern is ideal for rinsing, vehicle washing, siding, decks, patios, and other applications requiring wide, even coverage with reduced surface impact.

Maintenance Recommendations

• Flush the nozzle with clean water after each use.
• Inspect the orifice regularly for mineral deposits, debris, or wear.
• Clean clogged nozzles using an approved nozzle cleaning tool—avoid using wire or sharp objects that may enlarge the precision orifice.
• Store the nozzle in a clean, dry location when not in use.
• Use only genuine OEM replacement nozzles to maintain proper spray pattern, operating pressure, and long service life.