HOUGHTO-SAFE® NL1 | Water-Glycol Fire Resistant Hydraulic Fluid

ms and N-Line tensioner installations on offshore drilling and production vessels. Formulated to solve the specific degradation and residue formation problems that have plagued conventional water-glycol fluids in riser tensioner applications — HOUGHTO-SAFE® NL1 provides validated long-term pH stability, outstanding lubricity and full Cefas D environmental compliance.

Supplied through Orbit Industrial as an authorised Quaker Houghton distributor. Available in 209L drums and 1,000L IBC. Available by request for quote only — not available for direct checkout.

Product Data Sheet

The Riser Tensioner Problem — and Why NL1 Solves It

Degradation of hydraulic fluid in direct acting tensioner systems has been a documented issue in the offshore industry. Conventional water-glycol fluids can form sticky, high-viscosity black residues containing metal fines under certain operating conditions — residues that can deposit around sealing elements and accumulate in anti-recoil valve internals, creating a critical system failure risk. HOUGHTO-SAFE® NL1 has been specifically formulated to minimise such residue formation and maintain stable pH over a 5-year service period — validated in long-term OEM cylinder tests.

Features & Benefits

Feature	Advantage & Operational Benefit
Passes Def Stan 91-110 Annex D — 40:1 compression ignition ratio	Certified fire resistant performance — complies with defence and offshore fire resistance specifications for safety-critical hydraulic systems
Very high lubricity — validated in long-term OEM cylinder tests	Protects riser tensioner cylinder bore surfaces and sealing elements from accelerated wear — extending cylinder service life and reducing overhaul frequency
Excellent pH stability for 5 years or more	Prevents the pH-driven degradation and black residue formation that causes anti-recoil valve failure in conventional water-glycol tensioner fluids
Can be used as a preservation fluid for up to 5 years	Dual-purpose — active tensioner fluid and long-term preservation fluid — reducing the number of products required for riser tensioner system management
Cefas D OCNS Rating	Environmentally acceptable for maximum discharge — compliant with UK CEFAS and global offshore environmental discharge requirements
Compatible with most commonly used elastomers	Avoids seal compatibility issues in standard riser tensioner seal materials — note: avoid PU and FKM/FPM seal materials
Corrosion resistant in liquid and vapour phase	Protects cylinder bore surfaces — including uncoated, untreated low-alloy carbon steel — from corrosive wear under lower pH operating conditions
Compliant with global environmental regulations	Suitable for offshore operations in all major drilling jurisdictions worldwide

Typical Properties

Property	Value
Fluid Type	Water Glycol — HFC Fire Resistant
Kinematic Viscosity @ 40°C (cSt)	40
Flash Point	None (water-based)
Fire Resistance	Def Stan 91-110 Annex D — 40:1 ratio
pH Stability	5 years or more in service
Cefas Rating	D — OCNS Compliant
Seal Compatibility	Most elastomers — avoid PU and FKM/FPM
Preservation Life	Up to 5 years

Applications

• Direct acting riser tensioner (DAT) systems on semisubmersibles and drillships
• N-Line riser tensioner systems on offshore drilling vessels
• Motion compensation systems on offshore drilling and production platforms
• Safety-critical hydraulic installations requiring Def Stan 91-110 Annex D fire resistance
• Long-term preservation of riser tensioner systems during lay-up periods

Related Quaker Houghton Offshore Products

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• AQUALINK® HT804F VER2 — HP/HT Subsea Production Control Fluid
• HOUGHTO-SAFE® WL1 — Wireline Tensioner Fire Resistant Fluid
• ENSIS® DW 2462 — Dewatering Corrosion Inhibitor
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