Alfa Laval hygienic tank covers are engineered with a unified design logic focusing on stainless steel construction and controlled surface finishes. These systems are designed to prevent liquid ingress or spray-out during high-intensity CIP cycles. The specific suitability of a model is determined by its pressure rating, opening mechanism, and seal geometry, ensuring compatibility with various tank types and process duties.

Pressure rated covers for hygienic vessels

The HLSD-2 is the primary high-pressure option in the range. It features an outward-opening design secured by swing bolts which ensure complete tightness. A rigid hinge maintains the exact location of the cover and includes a stop mechanism at an angle of 20-30° beyond the vertical position. This safety feature prevents the cover from accidental closing. The HLSD-2 is designed for installation in pressure vessels according to AD 2000-Merkblatt and complies with PED 2014/68/EU Hazard Category IV for Fluid Groups 1 and 2. Available in sizes from 200 mm to 600 mm, its maximum allowable pressure is contingent on cover thickness and bolt count; for example, a 200 mm unit with 8 mm thickness is rated for 14.7 bar at 50 °C. The internal surface finish is Ra 0.8 µm and the unit operates across a temperature range of -10 °C to +250 °C.

Low pressure access for non-pressurised tanks

The LKDC family is designed for tank-top access where pressure is minimal. While sizes 306 through 620 are intended for non-pressurised use, the LKDC-202 can withstand up to 0.4 bar. These covers swing outward and must be positioned above the liquid level. A replaceable, self-sealing double lip seal prevents fluid spray during cleaning or transport. The wetted surfaces are acid pickled to Ra 0.8 µm as standard, or Ra 0.4 µm for 3-A approved versions. For low-pressure duty up to 1 bar, the LKDC-LPB and LKDC-LP models are engineering for vacuum conditions during cleaning but do not carry PED approval. The LP version includes a safety pin and springs on the handles to ensure controlled opening.

Visual inspection with glass lid covers

The Type C, CG, and CG-LP models offer high versatility for static tanks and road tankers. Type C covers support inward, outward, or sideways opening depending on the specific configuration. For applications requiring visual monitoring, the Type CG features a sodalime tempered glass lid suitable for non-pressure tanks. The CG-LP variant upgrades this design to handle 1 bar positive pressure and full vacuum. The glass components have a maximum operating temperature of 120 °C, and all wetted steel parts maintain a surface roughness of less than Ra 0.8 µm.

Non-sealing covers for balance tanks

The LKDS is a specialized stainless steel manway cover designed for applications where a watertight closure is not mandatory, such as dairy balance tanks. It is equipped with a splash guard to prevent liquid loss during CIP processes. As this model is not assembled at delivery, onsite assembly is required. It operates at atmospheric pressure within a temperature range of -20 °C to +90 °C. Wetted surfaces are finished to Ra 0.8 µm, excluding the welding zones, providing a hygienic surface suitable for pharmaceutical and food processing environments.