New Delhi, March 31 -- A shortage of sulphur due to the West Asia war and a Hormuz blockade is threatening to slow boiler manufacturing at Bharat Heavy Electricals Ltd (Bhel), according to two people aware of the development, at a time when its boiler order book remains full amid a revival in thermal power.

Sulphur, a yellow element, is used in producing industrial gases such as acetylene and hydrogen and welding consumables like electrodes, fluxes, and filler wires that support high-temperature fabrication of boiler components.

Now, a shortage of this commodity has forced the power equipment maker to dip into its "critical stock" for "emergency needs", said the first of the two persons cited above, both of whom spoke on the condition o...