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ASME Standard 115D-1969 — Recommended Practices for the Design of Lubricating Systems for Marine Steam Turbine Pumps for Various Ships Services
⚙️ ASME Standard No. 115D (1969), formally titled Recommended Practices for the Design of Lubricating Systems for Marine Steam Turbine Pumps for Various Ships Services, was prepared by Panel II of the Joint ASTM-ASME Committee on Turbine Lubricating Systems. It is the fourth in the 115 series of recommended practices: No. 115A, B, and C dealt respectively with generators, boiler feed pumps, and blowers, while this Standard covers the other types of steam-turbine-driven pumps, such as main condenser circulating pumps and main and auxiliary condensate pumps. The Standard was approved by ASTM on September 12, 1968, and by ASME on June 30, 1969, and it was issued as the minimum design basis and guidance document for auxiliary-machinery lubricating systems on board ships.
💡 The 115 series follows the same philosophy as Standard No. 111 for main propulsion turbines: system design, materials, and fire safety are treated with equal weight — but the object shifts from the main propulsion turbine to the smaller, more numerous, and more dispersed auxiliary pump units.
1. Background and Scope 📌
In the foreword, the Committee states that Panel II continues its efforts to develop design practices for shipboard steam-turbine-driven equipment. After standards 115A, B, and C for generators, boiler feed pumps, and blowers, this Standard covers other types of pumps, including main condenser circulating pumps and main and auxiliary condensate pumps. The document is divided into a general discussion section and three specific sections dealing with the various ways of lubricating and the various lubricants, so that the arrangement, capacity, and service conditions of different pump units can each be addressed.
The central purpose is to coordinate the efforts of the equipment builder, the erector, the oil supplier, and the operator toward satisfactory oil-system performance, by codifying practices that have proved effective in service. Of necessity the provisions are generalized and represent minimum requirements, because of variations in equipment, builders’ practices, and local conditions.
⚠️ Like Standard No. 111, 115D is a recommended-practice document, not a mandatory code. Its clauses are intentionally general and minimal; the engineer must still adapt them to the specific equipment, the builder’s practices, and the site conditions.
2. Lubricating System and Lubricant Types 🛢️
The Standard is organized into general chapters and specific chapters for particular lubrication approaches. For auxiliary pump units, the basic system types remain consistent with the preceding standards — gravity, pressure, and pressure/gravity systems. In addition, specific recommended practices are given for different lubricants and lubrication methods, matched to the service of each pump type, such as continuously operating circulating pumps or variable-load condensate pumps.
| Pump Type | Typical Duty | Lubrication Concerns | Suitable System Type |
|---|---|---|---|
| Main condenser circulating pump | Large cooling-water flow for the condenser | Continuous duty, high flow, frequent start/stop shock | Pressure or pressure/gravity |
| Main condensate pump | Recovery of main-engine condensate | Variable load, cavitation, seal lubrication | Pressure (with pressure stabilization) |
| Auxiliary condensate pump | Standby or small condensate flow | Intermittent starts, shutdown protection | Pressure |
| Other steam-turbine pumps | Miscellaneous ship services | Depends on arrangement and capacity | Per specific chapters |
3. Materials, Piping, and Valves 🔩
The materials chapter follows the philosophy of Standard No. 111: minimize copper, zinc, lead, and similar metals that catalyze oil oxidation; prefer steel for piping, tubing, valves, and fittings while accepting stainless-steel tubing; generally avoid cast iron except in non-critical locations; use high tin-base babbitt for bearing linings; prefer steel plate for tanks; and select gaskets, seals, and hoses that resist turbine oil up to 200°F.
| Item | Recommended Practice | Rationale |
|---|---|---|
| Copper/zinc/lead metals | Minimize use | Catalyze oxidation of turbine oil |
| Piping, valves, fittings | Steel preferred | Strength, fabrication, cost |
| Bearing linings | High tin-base babbitt | Conformability and embeddability |
| Tanks | Steel plate preferred | Strength and ease of cleaning |
| Gaskets/seals/hoses | Oil-resistant (up to 200°F) | Long-term resistance to oil |
Piping should be welded or flanged-and-bolted; screwed connections are not recommended and, if unavoidable, must be seal-welded. Valves should be easily accessible and replaceable, valves that can stop oil flow to the machinery must be locked against inadvertent closure, and all drain valves must be locked closed. Instrument connections should be designed and installed for maximum safety with adequate bracing, and piping must be protected from hot surfaces.
4. Coolers, Purification, Alarms, and Fire Safety 🌡️
Oil coolers must be sized to maintain the oil outlet temperature at values recommended by the machinery manufacturers; twin coolers are recommended for single-screw ships and one cooler per shaft for multi-screw ships; cooler bundles should be readily removable, with thermometers, vents, and drains. The oil purification system must be of sufficient size to handle the oil while the vessel is under way.
The table of contents lists dedicated chapters for Alarms and Fire Hazard, confirming that auxiliary pump lubricating systems must equally be provided with the necessary level, pressure, and temperature alarms, and that the possibility of oil contacting hot surfaces or ignition sources must be minimized through design and arrangement. The chapters on the design of pressurized lubricating systems and the design of pump lubricating systems set out specific requirements for system pressure, flow margins, control and seal oil needs, and the return-oil arrangements of the pump units themselves.
🚨 Auxiliary pump units are frequently located close to hot piping and heat sources. Their fire-protection layout must not be downgraded merely because they are “auxiliary” — the Standard treats fire hazard as a chapter of equal standing to that for the main system.
5. Engineering Practice Essentials ✅
- 🔍 Series coordination: 115D completes the 115 series (A: generators, B: boiler feed pumps, C: blowers, D: other pumps). Identify the pump type first, then apply the corresponding part.
- 🔧 System definition: large continuously operating circulating pumps suit pressure or pressure/gravity systems with stabilizing head; variable-load condensate pumps require close attention to seal-oil and control-oil pressure.
- 📐 Alarm configuration: level, oil-pressure, and oil-temperature alarms are essential for unattended or infrequently inspected auxiliary machinery and should be integrated into the engine-room monitoring system.
- 🔥 Fire layout: keep lube-oil lines of pump units away from ignition sources and hot surfaces; place periodically serviced components in safe locations.
- 🗝️ Valve administration: lock all hazardous valves and drain valves, and keep a register.
6. Frequently Asked Questions ❓
❓ Q: What distinguishes 115D from Standard No. 111?
A: No. 111 addresses the main propulsion turbine lubricating system, while the 115 series targets steam-turbine-driven auxiliary equipment. 115A/B/C already covered generators, boiler feed pumps, and blowers; 115D completes the series for circulating and condensate pumps and other pump types.
A: No. 111 addresses the main propulsion turbine lubricating system, while the 115 series targets steam-turbine-driven auxiliary equipment. 115A/B/C already covered generators, boiler feed pumps, and blowers; 115D completes the series for circulating and condensate pumps and other pump types.
❓ Q: Why does the Standard devote a separate chapter to alarms?
A: Auxiliary pump units often sit in corners of the engine room visited infrequently, so abnormal oil pressure, level, or temperature may go unnoticed without instrumentation. The dedicated alarms chapter embeds condition monitoring into the system design to provide early warning.
A: Auxiliary pump units often sit in corners of the engine room visited infrequently, so abnormal oil pressure, level, or temperature may go unnoticed without instrumentation. The dedicated alarms chapter embeds condition monitoring into the system design to provide early warning.
❓ Q: Are there special cooler requirements for auxiliary pumps?
A: Yes — following the main-system practice, twin coolers are recommended for single-screw ships and one cooler per shaft for multi-screw ships; bundles must be removable for maintenance, and thermometers, vents, and drains must be provided.
A: Yes — following the main-system practice, twin coolers are recommended for single-screw ships and one cooler per shaft for multi-screw ships; bundles must be removable for maintenance, and thermometers, vents, and drains must be provided.
❓ Q: How does 115D relate to the later Standard No. 120?
A: The 115 series concerns marine steam-turbine auxiliary machinery, whereas No. 120 turns to gas-turbine-generator lubricating oil systems. Both belong to the ASTM-ASME-NEMA turbine-lubrication recommended-practice series; their design philosophy is shared but their targets differ.
A: The 115 series concerns marine steam-turbine auxiliary machinery, whereas No. 120 turns to gas-turbine-generator lubricating oil systems. Both belong to the ASTM-ASME-NEMA turbine-lubrication recommended-practice series; their design philosophy is shared but their targets differ.
