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D6211-98 – Standard Test Method Technical Guide
🔍 Scope and General Requirements
This specification covers fully-formulated propylene glycol-base engine coolants for heavy-duty engines, including both concentrates and prediluted solutions. Concentrates are designed for use at 40 to 60 % propylene glycol by volume in water of suitable quality (see Appendix X1), while prediluted coolants with 50 volume % minimum are ready for direct use. These coolants provide effective protection against corrosion, cavitation, freezing, and boiling in both winter and summer conditions.
Both virgin and recycled propylene glycol are acceptable. Coolant concentrates meeting this specification require no supplemental coolant additive (SCA) until the first maintenance interval, after which SCA additions are guided by the engine manufacturer or SCA supplier. This specification does not cover extended service interval coolants.
⚙️ Additional Requirements and Specifications
Coolants must meet several critical requirements beyond general specifications. The coolant concentrate must protect against cavitation corrosion, commonly termed liner pitting, and prevent scaling on internal hot surfaces such as the engine head and exhaust manifold. Both concentrated and prediluted coolants must contain less than 50 ppm sulfate ion. Additionally, concentrated coolant must have less than 4 % total dissolved solids.
| 🟦 Parameter | 📏 Requirement |
|---|---|
| Propylene glycol concentration (concentrate) | 40 to 60 % by volume |
| Prediluted coolant concentration | 50 volume % minimum |
| Sulfate ion content | Less than 50 ppm |
| Total dissolved solids (concentrate) | Less than 4 % |
💡 Tip: Always use water of suitable quality as specified in Appendix X1 when mixing concentrates to maintain coolant effectiveness and prevent system issues.
📊 Compliance and Testing Methods
Compliance requires adherence to multiple ASTM standards. Coolant concentrates must meet Specification D5216, while prediluted coolants must conform to Specification D6257. Water quality is assessed via methods such as D1126 for hardness, D1293 for pH, and D4327 for anions. Compatibility of supplemental additives is tested per D5828. Test methods for cavitation corrosion and hot surface scaling are under development; until approved, mandatory requirements in Annex A1 apply.
| 📐 Standard | 🎯 Purpose |
|---|---|
| D1126 | Test Method for Hardness in Water |
| D1293 | Test Methods for pH of Water |
| D4327 | Test Method for Anions in Water |
| D5216 | Specification for Propylene-Glycol-Base Engine Coolant for Automobile and Light Duty Service |
| D6257 | Specification for Prediluted Aqueous Propylene-Glycol Base Engine Coolant |
⚠️ Warning: Sulfate ion content must be strictly less than 50 ppm to avoid corrosion risks. Regular monitoring is essential for heavy-duty engine cooling systems.
❓ Frequently Asked Questions
🔍 What is the required concentration for prediluted coolants?
Prediluted coolants must have a minimum of 50 volume % propylene glycol and are intended for direct use without additional dilution.
💡 When should supplemental coolant additive (SCA) be added?
SCA is not required initially for concentrates. The first dose is needed at the first maintenance interval, following engine manufacturer or SCA supplier instructions.
⚡ What is the sulfate ion limit for these coolants?
Both concentrated and prediluted coolants must contain less than 50 ppm sulfate ion to ensure systemic protection.
📌 Does this specification cover extended service interval coolants?
No, this specification explicitly excludes extended service interval coolants, which require distinct formulations and testing.