O-rings are the primary pressure sealing elements in all RV Power Group underwater connectors. Maintaining an adequate stock of correct O-ring replacements is the single most cost-effective maintenance action for any subsea connector system. A failed O-ring costs pennies; the consequence of a flooded instrument or connector body can cost tens of thousands in equipment loss and recovery operations.

At a glance: Nitrile (NBR) standard | EPDM and FKM (Viton) on request | Series-specific cross-sections and ODs | Kit packs and individual spares | Replace every 2–3 years or on any visual damage

Key Design Features

• Nitrile (NBR) Standard Material: Nitrile O-rings provide excellent seawater, hydraulic fluid, and drilling mud resistance at operating temperatures from −40°C to +120°C — the standard material for all RV Power Group connector series.
• EPDM Option — Superior Low-Temperature Performance: EPDM O-rings maintain flexibility to −55°C for Arctic operations, polar research, and cold-deep abyssal deployments where nitrile would stiffen and lose sealing force.
• FKM (Viton) Option — Chemical Resistance: FKM O-rings resist aggressive hydrocarbons, H₂S (sour gas), and methanol injection fluids — required for well-intervention tooling and production tree instrumentation exposed to wellbore fluids.
• Series-Specific Cross-Sections: O-ring AS568 or metric cross-section and OD are specific to each connector body groove — do not substitute generic O-rings without confirming cross-section and OD against the connector drawing.
• Multiple O-ring Positions Per Connector: Connectors typically have 2–4 O-rings: face seal, body seal, and cable entry seal. All must be replaced as a set to ensure system integrity.
• Pre-Greased Kit Packs: O-ring kits are supplied with the correct silicone grease sachets for immediate installation — no separate lubricant sourcing required at the offshore worksite.
• Colour-Coded by Compound: NBR = black; EPDM = grey; FKM = green/brown — enabling visual confirmation of correct O-ring installation without marking or labelling.
• Storage Life: Stored correctly (sealed bag, away from UV, ozone, and heat), O-rings have a shelf life of 5+ years — suitable for stocking in offshore spare parts containers.
• RV Power Group OEM Dimensions: Manufactured to the same dimensional tolerances as the original O-rings installed in the connector — guaranteed fit and sealing performance without modification.

Specifications

Why O-Ring Maintenance Is Critical

O-Ring Failure Is the Most Common Cause of Connector Flooding

Field studies of returned subsea instruments consistently identify O-ring degradation — compression set, swelling from chemical exposure, UV degradation, or mechanical damage during installation — as the leading cause of seawater ingress. Correct O-ring maintenance eliminates this failure mode entirely.

Replacement Interval

Replace all O-rings every 2–3 years of operational service, or immediately on any of the following: visible cracking, permanent flat spot (compression set >15%), swelling greater than 5% OD increase, surface tackiness or brittleness, or any seawater ingress event that required O-ring exposure.

Never Re-Use O-Rings After a Flood Event

If a connector has been flooded or subjected to pressure exceedance, replace all O-rings in that connector before redeployment — even if the O-rings appear undamaged. The event may have introduced micro-fractures invisible to visual inspection.

Correct Lubrication Is Mandatory

Always apply a thin, even film of silicone grease (e.g. Molykote 111 or equivalent) to the O-ring before installation. Dry O-rings tear during connector mating. Do not use petroleum-based greases — they cause NBR and EPDM to swell, compromising the seal.

Cross-Section and OD Must Match Exactly

An O-ring with incorrect cross-section will either not seal (undersized) or over-compress and extrude (oversized). Always verify cross-section and OD against the connector-specific O-ring drawing before installation. Contact RV Power Group for the correct O-ring specification for your connector model.

Frequently Asked Questions

Q: How often should O-rings be replaced?

A: Every 2–3 years in active operational service, or immediately on any visible damage, after a flooding event, or after a pressure exceedance.

Q: Can I use generic O-rings from a hardware store?

A: We strongly advise against it. Generic O-rings may be the correct OD and cross-section but use an inferior compound or durometer (hardness) that will not seal correctly at subsea pressure. Use RV Power Group OEM O-rings to guarantee sealing performance.

Q: What lubricant should I use?

A: Silicone grease — Molykote 111, Dow Corning DC4, or equivalent. Apply a thin even film to the O-ring surface only. Do not apply lubricant to the connector mating face or contact areas.

Q: Do I need to replace all O-rings at once?

A: Yes — replace all O-rings in a connector as a complete set at each service interval. Replacing only one O-ring and leaving others in place defeats the purpose of the inspection.

Q: How do I order the correct O-rings for my connector?

A: Contact  with your connector model number. We will provide the O-ring specification and supply kit packs for your fleet size.

Q: Are EPDM O-rings available for Arctic deployments?

A: Yes — EPDM O-rings rated to −55°C are available for all connector series. Specify EPDM when ordering for polar or deep-cold applications.

Q: What is the shelf life of unused O-rings?

A: 5+ years in original sealed, UV-protected packaging stored away from ozone sources (electric motors, UV lights). Once the packaging is opened, use within 12 months.

How to Order

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