Cable-Pulling Lubricant Quantity
Estimates the pulling lubricant a conduit run takes, so the crew does not run short mid-pull.
Example
You enter
- Conduit run length (ft) 400
- Conduit inside diameter (in) 3
- Film-coating K factor 0.0015
- Bend / fill multiplier 1
You get
- Lubricant to bring 1.8 gal
Checked against published worked examples from: American Polywater Corporation.
Details, formula, and sources
Scopegallons = K x length x conduit ID x bend factor. A 400 ft run in 3 in conduit wants about 1.8 gallons (round to a full pail), and a bend-heavy, high-fill pull at a 1.3 bend factor pushes that past 2.3. K is a film-coating rule (~0.0015, the common Polywater rule); under-lubing risks a stuck cable, so round up and keep a spare pail.
Formula or tablegallons = k_factor x length_ft x conduit_id_in x bend_factor (Polywater Q = k x L x D).
Source and editionFilm-coating lubricant estimate by name (gallons proportional to length x conduit ID, the wall area the film coats, scaled by a bend/fill factor); rule-of-thumb.
Free accessThe film-coating rule of thumb (~0.0015 gal per foot of run per inch of conduit ID) is public; the lubricant manufacturer's rate governs.
What governsEstimate. AHJ and licensed professional govern.
API field nameslength_ft, conduit_id_in, k_factor, bend_factor, gallons
- K factor ~0.0015 gal per foot of run per inch of conduit ID (Polywater Q = 0.0015 x L x D; 0.0008 L/m/mm metric)lubricant manufacturer
- Bend factor 1.0 for a straight run; raise it for multiple sweeps and high conduit fillfield judgment