British viscosity units

The units for K will depend on the units prescribed for the other terms. Thus, in the English system of units, if the pressure change is in psf (pounds per square foot), the distance is in feet, and the viscosity value is in Bvu s (British viscosity units of pounds/ft-sec), with the velocity in ft/sec, then the dimensions of K will be ft /sec. (It may be noted that the viscosity in poises has the dimensions of grams/cm-sec, and the viscosity in centipoises has the dimensions of centigrams/cm-sec. Accordingly, to convert a viscosity value in centipoises, multiply the value by 6.72 x 10 to yield the viscosity value in Bvu s.)... 

Thermal conductivity to convert watts per meter-kelvin to British thermal unit-feet per hour-square foot-degree Fahrenheit, multiply by 0.57779 and to convert British thermal unit-feet per hour-square foot-degree Fahrenheit to watts per meter-kelvin, multiply by 1.7307. Viscosity to convert pascal-seconds to centipoises, multiply by 1000. 

FIG. 11-28 Effect of viscosity on heat transfer in short-tiihe vertical evaporator, To convert centipoises to pascal-seconds, multiply by 10 to convert British thermal units per hoiir-sqiiare foot-degrees Fahrenheit to joules per square meter-second-kelvins, multiply hy 5.6783,... 

A list of symbols in Ind. Eng. Chem., 1947, 39, 438, is similar to that given here, except that no black letters are used, latent heat is A instead of /, coefficient of linear expansion is a and of volume expansion j5, quantity of heat is Q, Cpjcv is k or y., thermal diffusivity is a, viscosity is (JL, kinematic viscosity y, and British thermal unit B.t.u. 

In the United Kingdom the Ministry of Defence (MOD) has issued specifications DTD 5628-5633, which cover test procedures and performance requirements for a range of products. Five strength bands and four viscosities, from penetrating to thixotropic, are defined. The torque strengths are tested on M8 nuts and bolts and the shear strength in 12-mm pins and collars. The development of these specifications and the test procedures have been described by C. L. Brett at the MOD. The breakloose torque on nuts and bolts requires particular attention to a transient measurement where the first torsional motion is detected. Other products show somewhat different behavior, with no distinct breakloose, and the torque at which the sealant begins to yield is not easily detected [77]. British Standard BS 5292 relates to the use of anaerobic sealants on gas appliances. 

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