Manufacturing Process of Glazed Stoneware Pipes

Raw materials:

  • White clay
  • Grog
  • Water
  • Fuel
  • Coal

Screening section:

White clay mined in local quarries is brought into factory and stored in clay shed and grog ground in to crystal pears is feed inpan mill , which grinds both uniformly and the material is poured down and the same is lifted by bucket elevator carrying the ground material to over 40 feet height dropping the material on a steel mesh of specific size which allows only material of specific size , material bigger than the mesh size is returned via return pipe which drops the powder into pan mill which is again grinned and this is a continuous process where in only powder of mesh size only allowed to pass through the mesh.

Powder then is mixed with water uniformly and fed in to pug mill where clay is extruded into lumps of clay having good quantity of water in it.

Pipe Mill Section

Extruded lumps of clay are feed in to pipe mill and the same is extruded which sends lumps into barrel of pipe mill where vaccum is created which removes air from the lumps to give a perfect shape to pipes, these pipe are extruded down through the pipe mill where clay passes through dye of specific size and final pipe shape is brought out which is trimmed to accurate size required.

Drying section

After pipes re trimmed as per required size they are manually transported to drying area of the factory where they are lined up vertically and are allowed to dry for a day which are again trimmed to perfect round shapes with the help of hands by experts having good number of years experience. These pipes are now allowed to dry completely which takes a time period of 4 to 10 days depending upon weather conditions.

Kiln firing

Pipes which are dried are loaded in to kiln according a preset pattern depending upon pipe size, these pipes are are arranged according to the sizes. Then kilns are sealed with fire bricks and coal is feed in to choolas and fired to a temperature of 110 degrees centigrade upon reaching the required temperature samples are drawn out of the kiln to check whether they are fully burnt. Then a mixture of raw salt and magnesium dioxide is prepared which is feed into the kiln at regular intervals which in turn colors and glazes the stoneware pipes.

Then kiln is sealed and is allowed for about 4 days to cool and pipes are unloaded from Sorting of pipes

The kiln and are sorted after checking quality by hammering them with a light hammer , then all required tests specified in is 651-2007 are performed randomly based on lot, a quality control check is performed randomly from stacked pipes as a process of internal quality management.

The pipes are stacked in lots and marked with IS which are later loaded and transported to customers sites as required.

Process Flow Chart Illustrating

Manufacturing of Glazed Stoneware Pipes


(White clay and Grog)


(Both White clay and grog are fine crushed)


(Fine crushed material is lifted by elevator buckets)


(Fine crushed material is screened on mesh to get uniform powder)

(Water is added to Powder, Creating lumps of clay)


(Clay lumps are feeded to Pipe press)


( Clay lumps are extruded through required dyes forming pipes)

(Extruded pipes are trimmed to required sizes)


(Trimmed pipes are dried in shed under controlled temperature for a period of 4 to 7 days)


(Dried pipes are loaded into Kilns)

(Kilns are lit and temperature is raised with coal feeding until temperature is 1100 degree centigrade)

( Upon reaching 1100 degree  common raw salt feeded to kiln at certain intervals)

(Kiln is allowed to cool naturally)


( Finished pipes are unloaded and sorted according to quality in lots  and marked ISI after passing required tests specified by IS 651 with latest amendments from time to time)