Hot Topping Compounds

Hot Topping CompoundsHot Topping Compounds are a series of anti-piping compounds used as covering for casting risers to increase the feeding efficiency of the riser and at the same time confine shrinkage cavities to safe level in riser. Hot Topping Compounds when added on the surface of liquid metal burns immediately and later forms an insulating and porous crust thereby heat loss due to radiation is minimised. This helps to keep the metal in liquid state for longer time so that feeding to the casting is more efficient. Temperature of liquid steel in the riser is maintained properly. The rate of cooling of liquid metal in the riser is prolonged due to high insulation properties of the Hot Topping Compounds. In short Hot Topping Compounds keep metal more hot in riser area for a long time for efficient feeding so as to avoid casting rejection due to shrinkage, porosity, piping etc. and casting produced are sound and pressure tight. GRADES OF HOT TOPPING COMPOUNDS:  EXOTHERMIC TYPE (NON EXPANDING TYPE) H.T.C.-22 : The powder being exothermic in nature burns intensively when it comes in contact with liquid metal in the riser. It is non carbonaceous and heat output is rapid. Powder after burning forms a hard insulating crust. Fume level is moderate. Recommended for steel casting up to 3"-4" I.D. risers. H.T.C.-110 : This is a thermit type anti-piping compound and highly sensitive to heat. Non-carbonaceous Forms a hard crust. High heat output. Recommended for cast iron castings up to 6" I.D. risers. H.T.C.-505 : Thermit type compound and highly exothermic. Burns intensively and forms a hard crust. Non-carbonaceous. Recommended for steel castings above 4"-5" I.D. risers. EXOTHERMIC TYPE (EXPANDING TYPE) H.T.C.-K9(B) : This product is mode rate exothermic in nature but highly insulating type and have expanding properties, forms a soft crust which is brittle in nature. The crust can be removed easily from the riser head. The powder has excellent flow-able properties and spreads evenly on the liquid surface and stops radiation of heat to atmosphere. The product is rec0mmened for use for steel casting risers from  6"-12" I.D. H.T.C.-K9(B) is also ideally used along-with insulating hot tops for the production of steel ingots. The fume level is very low. H.T.C.-20(N) : Highly exothermic but more of expanding type. The powder after coming in contact with liquid metal swells and acts as a thorough insulating cover to avoid heat loss due to radiation. Powder spreads evenly on the liquid surface. Crust is powdery. Fumes are very low. Requirement of powder is less as it has good expanding properties. The product is recommended to be used along-with insulating Hot Tops and Sleeves for the production of castings and ingots. (Riser size up-to 6" ID and Stainless steel ingots - 200 to 600 kg) H.T.C.-K-20 : This pro duct is highly exothermic and expanding anti piping compound specially to be used in conjunction with exothermic Hot Tops used in the production of stainless steel ingots up-to size of 8" Sq. Other properties are similar to HTC- 2ON. ADVANTAGES : Easy addition. Rejection due to shrinkage cavities totally avoided. HOT TOPPING COMPOUNDS do not introduce any impurities in the riser metal. Riser heads can be safely re-melted. Economical in use. Better and efficient feeding. No obnoxious fumes. PACKING : 50 Kg moisture-proof polythene lined gunny bags.