Bergen-Paterson HSSA NF Hydraulic Arrestors are supplied with General Electric SF 1154 fluid to meet all snubber applications. SF 1154 methly phenyl polysiloxane silicone fluid is a clear, light straw colored liquid, which possesses even better heat stability than the dimethyl polysiloxane (SF96-XXX) silicone materials which were previously supplied as the standard fluids in non-radiation applications. SF 1154 has outstanding heat resistance which is combined with low volatility and high flash point to provide a normal useful service temperature range of -40°F to +500°F. In addition, SF 1154 has excellent high temperature heat transfer characteristics which minimize localized heat spot- ting sources and aid energy dissipation during cyclic loading conditions.
The SF 1154 silicone fluid working in conjunction with unique chemical conversion dry film lubricants forms a lubrication system in the Hydraulic Arrestor which minimizes wear and prolongs service life. This system helps reduce the high break-in wear associated with new equipment and sets up the dual-seal cast iron piston rings as an excellent high pressure metallic seal.
The high energy (heat or radiation) resistance of the fluid is a result of the chemical structure of the silicone oxygen molecule. Where organic hydrocarbons fluids are based on a backbone of carbon-to-carbon atoms, the silicone fluid has a backbone of silicone-oxygen linkages similar to the Si-0 linkages in other high temperature materials (quartz, glass and sand). It is this Si-0 linkage that contributes to the outstanding broad-temperature characteristics and general inertness of the silicone fluid.
Some of the outstanding properties of the silicone fluid are:
- Low Viscosity Temperature Change –
All fluids change viscosity with temperature change but GE SF 1154 silicone fluid exhibits a much smaller change than non silicone fluids. - Wide Temperature Range –
SF 1154 has a useful range of -40° to 500° F. which far surpasses conventional fluids. - Excellent Thermal Stability-
SF 1154 has shown excellent stability when exposed to very high temperatures. - Excellent Oxidation Stability –
Due to the absence of copper-induced oxidation, the sludging that normally occurs with mineral oils, especially at high temperatures, is eliminated. No evidence of sludging has been reported in service.
- Chemical Inertness –
SF 1154 fluid is chemically inert to most common materials. - Non-Flammability-
SF 1154 is self-extinguishing. The flash point is in excess of 550°F, along with a fire point exceeding 650°F and an auto ignition temperature in the range of 880°F to 900°F. - Excellent Shear Stability –
Silicone fluids have unusually high resistance to breakdown by mechanical shearing. The shear sta- bility of silicone fluids can be as much as 20 times that of quality petroleum oils, providing long life. SF 1154 normally does not require change during the design life of the Arrestor. - Excellent Heat Conductivity –
The thermal conductivity of SF 1154 is relatively constant over its wide temperature range, making it ideal as a working fluid for Hydraulic Arrestors. - Non-Corrosive-
GE SF 1154 contains no acid producing chemicals to cause staining or corrosion.
- Radiation Resistance –
GE SF 1154 is rated serviceable at 1 X 108 roentgens which far exceeds normal nuclear plant design radia- tion levels.
TYPICAL PROPERTIES* of SF 1154 SILICONE FLUID
| 1. Nominal Viscosity @ 77°F | 175 190 centistokes |
|---|---|
| 2. Viscosity Temperature Coefficient | .78 |
| 3. Specific Gravity @77°F | 1.050 |
| 4. Pour Point | -40°F |
| 5. Flash Point | >550°F |
| 6. Fire Point | >650°F |
| 7. Auto Ignition Temperature | 880°F 900°F |
| 8. Specific Heat BTU/lb/°F | .39 |
| 9. Radiation Resistance | 1 X 108 Roentgens Min. |
| 10. Toxicity | Low to None |
| 11. Storage Life | Indefinite |
| 12. Bulk Modulus @ 100° F | 245,000 psi |
*The properties listed are typical and should not be used as specification limits. Specific details and test properties may be obtained from the General Electric Company, Waterford, New York.
Due to the inertness and stability of SF 1154 fluid, apparent discoloration noted during seal overhaul can be removed prior to filling, by filtration. The discoloration or streaking of dark particles dispursed in the fluid are normal wear and film particles resulting from wearing in and honing surfaces. Filtration of the fluid through a 10 micron filter element will remove the particles and restore the fluid to cleanliness levels as originally provided during filling and final testing at the factory.
SF 1154 fluid is soluble in most alcohols and glycols except Ethylene and Propylene glycols, glycerine and carboway 300. It is also soluble in most hydrocarbon and vegetable oils along with hydrocarbon solvents. The fluid as with the Ethylene-Propylene seals used in the Hydraulic Arrestor should not come into contact with these solvents. If contaminated, discard and recharge the Arrestor with clean fluid.