Steel cylinder pipe with concrete lining and coating
1989 Edition

According to the provisions in Clause 4.1 and Table 8.1 of the standard, the minimum steel plate thicknesses vary with pipe diameter as follows:

Clause 8.2 reiterates that plate thickness must not fall below these values to maintain structural integrity for applications such as water mains, sewerage, and irrigation systems.

The code specifies that concrete lining must be applied exclusively at the manufacturer's facility, while coatings may be applied either at the factory or on-site. Coating should commence only after a minimum of three days post-lining completion or when the lining reaches a compressive strength of at least 10 MPa, during which proper curing is mandatory. Application methods for coatings include vibration, pressure application using rotary brushes, or guniting. The finished lining and coating surfaces must be dense, smooth, and free of laitance or irregularities, with any projections exceeding 3 mm removed by trowelling or grinding. Minimum thicknesses as per Table 2 are:

The standard mandates a minimum reinforcement amounting to 3% of the steel content in the cylinder based on the minimum plate thickness from Table 1. Reinforcement can be provided as spirally wound wire or wire fabric mesh. When coatings are applied using vibration, longitudinal reinforcement is compulsory. All reinforcement must conform to IS 432 (Parts 1 and 2) for mild steel wires and fabric. Wire ends and splices should be welded or anchored suitably, and wire tensioning between 50 to 75 MPa is recommended prior to coating. Coating application must occur before any corrosion develops on the reinforcement and after the lining has attained minimum strength or curing duration.

The classification of steel cylinder pipes with concrete lining by hydrostatic test pressures is as follows per Clause 3.1:

Working pressures are typically taken as 50% of test pressure for pumping mains and 67% for gravity mains. Hydrostatic testing must be performed before concreting, maintaining pressure for a minimum of one minute while checking for leaks. The maximum permissible tensile stress in the steel during testing is limited to 200 MPa.

Defects in lining and coating include voids, pockets filled with sand or clay, blistering, thin or hollow sounding areas, excessive cracking, or sections not adhering to the pipe surface. Cracks that allow a 0.8 mm flat metal gauge to penetrate halfway through the lining or coating and spaced less than 75 mm apart are considered defective; superficial hairline cracks are acceptable. Protrusions exceeding 3 mm must be removed by trowelling prior to setting or grinding after curing. Repair involves removing defective areas and restoring them with dense, hard, and smooth material free from laitance, ensuring full contact with the pipe surface and absence of voids. These repairs must be inspected and accepted before final approval.