Valve Maintenance Guide

Hydrofluoric Acid, higher called HF acid, is a enormously corrosive acid that is observed in alkylation refineries. The alkylation technique is used to produce fuel for automobiles and plane, and is dangerously corrosive.

In order to fulfill the task of the corrosive alkylation environment, valves used inside the HF Acid procedure are often fabricated from monel body and trim, or at least Monel trim. Most alkylation flowers round the sector are made to specs certified through UOP or ConocoPhillips (formerly Phillips), and handiest a handful of manufacturers are authorised by these corporations to be used in their alkylation strategies. Amongst them are Italy’s Petrolvalve.

Monel valves come in an expansion of configurations, but the 3 kinds which can be certified underneath UOP and ConocoPhillips specs are monel gate valves, monel globe valves, monel check valves and monel plug valves. Although butterfly and ball valves also can be used, these are presently not inside the UOP / ConocoPhillips license variety.

Monel valves, such as those product of A494 M-35-1 in forged form are frequently determined in HF Acid flora and used in the maximum stressful alkylation programs. Under DIN norms, frequently used in Europe, they targeted as 2.4360, or 2.4361, as well as 2.4375. Other programs for the use of monel valves are desalination plant life, and different saline and marine environments, plus highly explosive and at instances corrosive oxygen carrier — where valves need to be degreased, securely located in airtight bads and require special tagging.

Monel valves utilized in hydrofluoric acid applications typically meet the highest industry standards, which includes but no longer constrained to:

— An overlay of nickel at the backseat to face up to the corrosive alkylation environment.

— Special paint that modifications shade and tone upon contact with HF acid.

— Bar inventory monel stem make of K500 alloy, that’s age-hardened and will increase tensile energy and resistance to acid.

— The joints and lapped individually to assure a easy and wonderful seal, and prolong the valve’s lifestyles at the provider line.

— Monel seats are welded into the valves. This procedure reduces the chance of leakage and provides a bubble-free seal near the stem. Lapping and welding ensure to reduce in addition corrosion, because the valve may not be easily accessed once it’s far in service.

— API six hundred wall weights.

— Fugitive Emissions requirements are also applied to monel valves for alkylations carrier, ostensibly for employee safety.

UOP and ConocoPhillips often revise the standards of their authorized producers of monel valves to ensure that each one industry and safety standards are met. Some sources of monel gate valves and monel globe valves additionally inventory and distribute hf acid valves on brief shipping schedules.