Steel Smelting Blast Furnace Gate Valve

The Challenge

SpiralWeld™ was approached by an experienced valve servicing company to support ReManufacture+ of a steel smelting blast furnace gas control wedge gate valve. The material supporting Stellite control surface had experienced heavy erosion and corrosion from the high temperature, high mass flow and chemically corrosive process gases continually passing through and valve performance was lost as a result, impacting blast furnace operation and efficiency.

The valve control face tapered on a 2⁰ angle from open to close thus a solution was required to ensure the correct dimensional requirements were achieved during recovery.

Due to the valve obsolescence and resulting operational losses a SpiralWeld™ ReManufacture+ solution was most cost and time effective making it possible to meet our customer’s urgent delivery requirement.

Solving the Problem

In accordance with SpiralWeld™ ReManufacture processes, all critical dimensional data was recorded, with attention given to the critical control face geometry using our in-house 3D coordinate measuring equipment. Material composition analysis was performed using our in-house X-Ray fluorescence capability to identify original parent material and ensure correct weld consumable selection. Engineering review of potential recovery options allowed the SpiralWeld™ team to determine and validate that the final ReManufacture+ solution would meet the customer’s technical requirements, within the required cycle time.

The eroded and corroded seat was pre-machined to sufficient depth to ensure clean parent material was reached. A new fixed body seat was designed and manufactured with the correct 2⁰ wedge gate asymmetric feature to the Seat face. A new seat donor ring was manufactured from an equivalent material for inserting into the valve body fabrication, by our SpiralWeld™ process without distortion and with the carefully controlled installation critical to ensure precise alignment of the angle with the mating wedge gate. Our advanced cobalt-chromium hard-facing was applied to the seat face using the SpiralWeld™ process to provide an upgrade to the control seat performance and working life. This gave the valve improved toughness to withstand exposure to the furnace gases, improving reliability and extending working life for a fraction of the cost and time required for a new valve of original, non-upgraded design.

A Successful Outcome

The delivered valve was completed in accordance with the SpiralWeld™ ReManufacture+ process, which guarantees improved performance over the original design.

The customer required the ReManufacture+ process be carried out in the swiftest possible time and SpiralWeld ™ was able to support this, with a cycle of 10 days from initial engineering to dispatch, including all material supply from our in-house stocks.