Speed WEY HSI explosion isolation gate valves
These fast-action dampers are most robust, heavy-duty explosion isolation systems. The operating principle is similar to knife gate valves, but the trigger response and closing times are extremely short. The small-diameter versions are extremely resistant to explosion pressure and rated up to 50 bar (larger versions are rated up to 30 bar). These ratings are most likely to occur with explosion of gas and dust mixtures. In standard applications, the fast-action explosion isolation gate valves can be used with dust, gas or gas and dust mixtures. Not unlike HRD systems, the explosion isolation gate valves are triggered by dynamic pressure and/or flame sensors, and the whole explosion isolation system is managed by a dedicated control unit.
The fast-action explosion isolation gate valves can be operated as certified explosion isolation systems in installations designed to withstand the maximum possible explosion pressure (i.e. 10 bar by design). The list of equipment systems this explosion isolation solution can be applied in is practically limited by the ductwork diameter only, the maximum of which is DN400. The applications include filters, cyclone separators, processing reactors, dryers, pressure tanks, silos, and grinding mills. The only drawback of the solution is a very high price, especially in the large diameter spectrum. However, the benefit is a system which can be restarted independently by the user following an explosion, with no need for a field service call. This is essential for those processing systems where the minimum shutdown time is critical.
Applications:
- Explosion protection of processing devices and equipment units (including grinding mills, silos, separators, dryers, mixers, etc.) against combustible and flammable dust (class ST1 and ST2) and gas and dust mixtures;
- In-line installation of the solution in the interconnection ductwork / piping to ensure protection against explosion pressure: especially in conditions where reduced explosion pressure may cause damage;
- The explosion isolation gate valves can be operated in systems with constant presence of dust in the flowing medium.
Specifications:
- The explosion isolation gate valve ensures an unchanged clear surface area of the ductwork and prevents deposition of materials;
- Can be installed at any orientation and features a two-directional closing action;
- DN 100 to DN 400 models resist 24 bars of pressure;
- Driven by a pneumatic operator supplied at 6 bars from the on-site compressed air system;
- Made of stainless steel or better materials (available in a clean-room version)
- Application limits:
- Dust with a steady max. Kst ≤ 300 bar × m/s;
- Gas and dust mixtures with a steady max. Kst ≤ 500 bar × m/s;
- Ex protection type: II 1DG IIA 135 C / II 2D 3D IIB 135 C, permitted operating Ex-zones (internal / external): 20 / 21 and 0 / 2.
