Extra low freezing

Expls that do not freeze when exposed to temps as low as 35°F(+ 1.67°) are called LF(low-freezing), those not freezing at 0s F(—17.78°) are ELF(extra low-freezing) and those not freezing at lower temps are NF(qod-freezing). Ref US BureauMinesBull 346, (1931),27—29 Frictional Impact Sensitivity Test. See under Friction Sensitivity Teat Friction Pendulum Test, See under Friction Sensitivity Testa... 

When a part of NG is replaced with NGc (Nitroglycoi), the so-called LF (Low-Freezing) Gelatins are obtd. When part of NG (and of NGc) is replaced with AN (Ammonium Nitrate) in such quantities as to produce the same strength as before the replacement, the expl becomes Extra LF Gelatin (Ref 5)... 

It also has to be mentioned that if the freeze-dried product solvent is a mix of water alcohol, for instance, the condenser will have to be fitted with an extra low-temperature condensing unit (i.e., liquid nitrogen or other) loeated before the vacuum pumps. 

EPDM roof sheet is one of the lightest roof membrane materials because of its low specific gravity. It is highly suitable for lightweight structures and puts negligible extra load on the roof to be waterproofed. It is serviceable over a wide range of temperatures -50 °C to 150 °C, and the membrane does not embrittle in freezing condition nor soften in hot weather. 

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