NSF ANSI 20:2016 pdf free download – Commercial bulk milk dispensing equipment
5 Design and construction
This section contains design and construction requirements for equipment covered within the scope of this Standard. Unless otherwise specified, splash zone design and construction requirements shall apply to the interiors of bulk milk dispensers in which bulk milk containers are held.
5.1 General sanitation
5.1.1 Bulk milk dispensers shall be designed and manufactured to prevent the harborage of vermin and the accumulation of dirt and debris, and to permit the inspection, maintenance, servicing, and cleaning of the equipment and its components.
5.1.2 Bulk milk dispensing equipment shall be designed so that bulk milk containers may be added and removed and milk may be dispensed in a sanitary manner.
5.1.3 Food zones shall be readily accessible and easily cleanable or shall be designed for in-place cleaning when a readily accessible design is not feasible.
5.1.4 Food zones for which in-place cleaning is intended shall be designed and manufactured so that cleaning and sanitizing solutions may be circulated or passed throughout the fixed system. The design shall ensure that cleaning and sanitizing solutions contact all food contact surfaces. The system shall be self- draining or capable of being completely evacuated. Equipment and appurtenances designed for in-place cleaning shall have a section of the cleaned area accessible for inspection or shall provide for other acceptable inspection methods. The manufacturer shall provide written instructions for the cleaning and sanitizing of all food zone surfaces for which in-place cleaning is intended. The type and concentration of sanitizing agent recommended in the instructions by the manufacturer shall comply with 40 CFR part 180.940.
5.4.2 Permanent joints and seams in a nonfood zone shall be closed. Welded joints and seams in a nonfood zone shall be deburred.
5.4.3 Joints formed by overlapping sheets of material shall not create upwardly facing horizontal ledges (see figure 1b).
5.4.4 Sealants shall only be used to seal joints and seams that are structurally sound and are less than in (0.13 in, 3.2 mm) wide before sealing. Sealants may be used to fill spaces around collars, grommets,and service connections.
5.4.5 Solder and other fllet material shall be securely bonded to its substrate. All flux and catalytic materials shall be removed.
5.5 Fasteners
5.5.1 Fasteners shall not be used in a food zone.
5.5.2 Fasteners shall be easily cleanable. Fasteners meeting this requirement include, but are not limited to, slot-head and Phillips-head screws, hex head fasteners, and flush-break pop rivets. Hex key screws and non-flush-break pop rivets may be used in a splash zone or a nonfood zone provided that the heads are capped or flled.
5.5.3 Fasteners shall be tight ftting to the surface, except as permitted in 5.5.4.
5.5.4 No more than one locking washer and one flat washer shall be used per fastener head. The diameter of the washer adjacent to the fastening surface shall not be less than the diameter of the washer under the fastener head. External-tooth lock washers shall not be used.
5.5.5 There shall be no exposed threads, projecting screws, or studs in a food or splash zone. There shall be no more than 2.5 exposed threads or /4 in (0.25 in, 6.4 mm) of exposed threads, whichever is less, in a nonfood zone. Exposed threads on electrical cord strain relief devices in a nonfood zone shall be exempt.
5.5.6 The sharp point of a fastener shall not be exposed.