The Use of Monel Valves for Corrosion Resistance in Hydrofluoric Acid Applications

Hydrofluoric Acid, higher often called HF acid, is a extremely corrosive acid that’s present in alkylation refineries. The alkylation course of is used to supply gas for autos and plane, and is dangerously corrosive.

In an effort to meet the problem of the corrosive alkylation setting, valves used within the HF Acid course of are sometimes made fromĀ monel physique and trim, or at the least Monel trim. Most alkylation vegetation all over the world are made to specs licensed by UOP or ConocoPhillips (previously Phillips), and solely a handful of manufacturers are authorised by these firms to be used of their alkylation processes. Amongst them are Italy’s Petrolvalve.

Monel valves are available quite a lot of configurations, however the three varieties which can be licensed below UOP and ConocoPhillips specs are monel gate valves, monel globe valves, monel examine valves and monel plug valves. Though butterfly and ball valves can be used, these are presently not within the UOP / ConocoPhillips license vary.

Monel valves, resembling these made from A494 M-35-1 in cast type are sometimes present in HF Acid vegetation and utilized in essentially the most demanding alkylation purposes. Below DIN norms, typically utilized in Europe, they specified as 2.4360, or 2.4361, in addition to 2.4375. Different purposes for using monel valves are desalination vegetation, and different saline and marine environments, plus extremely explosive and at occasions corrosive oxygen service — the place valves must be degreased, securely positioned in hermetic bads and require particular tagging.

Monel valves utilized in hydrofluoric acid purposes usually meet the best business requirements, together with however not restricted to:

— An overlay of nickel on the backseat to withstand the corrosive alkylation setting.

— Particular paint that adjustments coloration and tone upon contact with HF acid.

— Bar inventory monel stem make of Ok500 alloy, which is age-hardened and will increase tensile power and resistance to acid.

— The joints and lapped individually to ensure a clear and constructive seal, and delay the valve’s life on the service line. You can buy online general purpose adjustable needle valves.

— Monel seats are welded into the valves. This process reduces the chance of leakage and supplies a bubble-free seal near the stem. Lapping and welding guarantee to cut back additional corrosion, because the valve won’t be simply accessed as soon as it’s in service.

— API 600 wall weights.

— Fugitive Emissions requirements are additionally utilized to monel valves for alkylations service, ostensibly for employee security.

UOP and ConocoPhillips continuously revise the requirements of their authorised producers of monel valves to make sure that all business and security requirements are met. Some sources of monel gate valves and monel globe valves additionally inventory and distribute hf acid valves on quick supply schedules.