Ansul Retaining Ring #20 (5 Pack) 415856

The Ansul 415856 is a 5-pack of Retaining Ring #20, for use with cartridge operated fire extinguishers only. The retaining ring secures internal components within the extinguisher valve assembly of cartridge-operated ANSUL units — holding valve parts in their correct position to ensure proper actuation when the cartridge is punctured and the pressurizing gas initiates discharge. A deformed, corroded, or missing retaining ring is an immediate NFPA 10 service deficiency that must be corrected before the extinguisher is returned to service.

Cartridge operated extinguisher designs differ from stored-pressure extinguishers in that the propellant gas is held in a separate cartridge rather than pre-charged in the main cylinder. When actuated, a puncturing mechanism pierces the cartridge, releasing gas that pressurizes the agent cylinder and drives agent through the discharge path. The retaining ring plays a critical role in maintaining the precise positioning of internal components throughout this actuation sequence — any looseness or damage in the ring can cause valve component displacement that results in a partial or failed discharge.

The 415856 5-pack is the correct service quantity for shops performing high-volume cartridge operated fire extinguisher and cartridge operated extinguisher fleet service. Available through authorized ansul distributors as part of the ANSUL fire extinguisher parts catalog. Replace the retaining ring at every internal examination as part of complete valve service, and document the replacement on the extinguisher inspection tag and fire extinguisher service tags per NFPA 10 requirements.

Inspect the retaining ring at every NFPA 10 annual inspection and internal examination of cartridge operated Ansul extinguishers. Check for deformation, corrosion, and secure seating in its groove. Replace with a new #20 retaining ring from the 415856 pack if any defect is found — never reinstall a deformed or corroded retaining ring. During the 6-year internal examination, replace the retaining ring as standard practice regardless of apparent condition. Document all retaining ring inspections and replacements on the extinguisher inspection tags and annual fire extinguisher inspection tags per NFPA 10. Note: the 415856 is for cartridge operated extinguishers only — do not use on stored-pressure extinguisher valve assemblies where different retaining hardware is specified.

What is the difference between cartridge operated and stored-pressure extinguishers?

A cartridge operated fire extinguisher stores the propellant gas in a separate puncturable cartridge rather than pre-pressurizing the agent cylinder. When actuated, the cartridge is pierced, releasing gas that pressurizes the agent. Stored-pressure extinguishers keep the propellant pre-mixed with the agent in a single cylinder. The two designs have different valve assemblies and service requirements — the 415856 retaining ring is for cartridge operated extinguisher valve assemblies only. Ansul's cartridge operated extinguisher line includes the ANSUL 101 and related models.

Is the #20 size the only retaining ring for ANSUL cartridge extinguishers?

Different ANSUL cartridge operated extinguisher models may use different retaining ring sizes. Always verify the correct size using the ANSUL fire extinguisher parts list for the specific model being serviced. Never substitute a different ring size — an incorrect retaining ring will not provide the correct retention force and can allow valve component displacement during actuation.