API 662:2006 pdf download
API 662:2006 pdf download.Plate Heat Exchangers for General Refinery Services-Part 1—Plate-and-Frame Heat Exchangers.
7.5 Corrosion allowance
7.5.1 Corrosion allowance, if specified, shall apply to unlined connections only.
7.5.2 The corrosion allowance for plate material shall be zero.
7.6 Components
7.6.1 Plates shall conform to the following:
a) the nominal thickness of gasketed plates before being pressed shall be sufficient to meet design conditions but shall not be less than 0.5 mm (0.02 in);
b) the plates shall be fully supported by the carrying bar;
C) the plates shall be designed to meet the design conditions without the need of additional stiffeners attached to the plate, unless otherwise approved by the purchaser:
d) the thickness of pass plates shall be sufficient to withstand the total stream pressure drop across the port area;
e) the wetted surfaces of supports for pass plates shell be of the same material as the plates:
I) al gasketed and semi-welded plates shall have permanently stamped identification for proper assembly:
g) end plates shall be furnished at the fixed and movable covers.
7.6.2 Fixed and movable covers shall conform to the following:
a) Covers designed with the use of stiffeners shall require approval of the purchaser;
b) Covers shall be furnished with slotted holes for tie bolts. The design shall mechanically restrain the tie bolts or nuts from turning.
7.6.3 TIe bolts and nuts for gasketed and seml.welded plate packs shall conform to the following:
a) the nominal diameter of tie bolts shall be at least 16 mm (5F8 in);
b) each tie bolt shall have one captive nut and at least one running nut. The length of each nut shall be greater than or equal to that of a heavy hexagonal type;
c) hardened steel washers shal be provided under all rotating nuts;
d) each tie bolt shall be supplied greased and with a plastic sleeve to protect It from the environment.
7.6.4 The carrying bar for gasketed and semi-welded plate-and-frame heat exchangers shall conform to the following:
a) the bearing surface shall permit easy sliding of the plates and movable cover along the entwe length of the carrying bar;
b) the carrying bar shall be designed to support at least 1,5 times the total mass of the movable cover and plate pack with the maximum number of plates filled with water (or the process fluid if its density is greater than that of water).
7.6.5 Gasketed and semi-welded plate-and-frame heat exchangers shall have a support column with a mounting foot located at the movable cover end A minimum of two mounting feet shall be provided at the fixed cover, The vendor shall design the supports for the external loads specified in the equipment data sheet or requisition documents.
• 7.6.6 If specified by the purchaser, the vendor shall provide details of the reacbon at the support pcNnts
C 7.6.7 If specified by the purchaser, plate-and-frame heat exchangers shall be equipped with a shroud to protect against spray leaks.
• 7.6.8 If specified by the purchaser, a suitable fire protection shroud shall be provided. The level of protection shall be specified by the purchaser. For further information see A.6.
• 7.6.9 If specified by the purchaser, plate-and-frame heat exchangers shall be equipped with a drip tray.
7.6.10 All units shall have two earthing lugs. one connected at each end of the frame.
7.7 ConnectIons
7.7.1 ConnectIons shall be bolted and shall be of either studded or flanged design. For flanged design, the connection shall be welded to the cover,
7.7.2 The use of studded and/or flanged connections and facings shall be specified on the data sheet.
7.7.3 DrIlled and tapped holes for studded connection bolts shall not pass completely through the cover plate The hole shall be threaded for a minimum length of one times the stud diameter and the miriamum undriHed thickness remaining in the cover shall be no less than one-fourth of its thickness.
7.7.4 The plate-and-frame heat exchanger shall be self-draining and self-venting through the connections for all pass arrangements.
7.7.5 For alloy-lined connections, the minimum thickness of the lining shall not be less than the plate thickness.
7.7.6 The projection of flanged connections shall be of sufficient length to allow Installation and removal of the flange bolts from either side of the flange.
7.7.7 All bolt holes for flanged or studded connections shall straddle centrelines.
7.7.8 Connection sizes of DN 32 (NPS 1-114). ON 65 (NPS 2-112), ON 90 (NPS 3-1/2) or ON 125 (NPS 5) shall not be used.
• 7.7.9 For alloy nozzles, the purchaser shall define requirements for either solid or lined connections. including any connections fitted into the nozzle necks.
