METHOD TO APPLY BALLAST MATERIAL ONTO SURFACE OF PIPE FOR UNDERWATER PIPELINE Russian patent published in 2011 - IPC F16L1/24 

FIELD: construction.

SUBSTANCE: method to apply ballast coating onto surface of pipe of underwater pipeline consists in the fact that pipe with fixed alignment rings is placed into external shell, so that ends of pipe protrude beyond the limits of shell, and between external surface of pipe and internal surface of shell there is a circular space. Circular plugs are installed at the ends of shell at least in one of which there is a hole with dimension close to gap between pipe and shell. They are fixed on pipe or in shell. Concrete pump is used to inject ballast material mortar into circular space through holes in one or both covers, and mortar consists of cement, water and additives and heavy spar ore as filler at the following content of components in wt %: cement: 12-17; water: 6-9.5; ratio of water to cement: 0.49-0.56; plasticiser: 0.2-0.3; heavy spar - balance, at the following content of fractions in wt %: large fraction of 5-25 mm 8-16; fine fraction of 0.16-5 mm 70-84; very fine fraction of 0.01 mcm - 160 mcm 8-14, at the same time mobility of injected ballast material defined by GOST 10181-2000, is in the range of 19-25 cm.

EFFECT: when using suggested method, ballast material of high density arrives into circular space with sufficient speed providing for high efficiency of process, and does not flake into fractions with separation of water and settling-out of large heavy grains of filler.

5 cl, 1 dwg, 2 tbl