NAF-Check Tilting Disc Check Valves PN 10 - PN 100, NAF Fk 30.70(6)GB 03.03

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1 NAF-Check Tilting Disc Check Valves PN 10 - PN, NAF Fk 0.70(6)GB 0.0 Characteristics The NAF-Check valve is available in BS, DIN and SS standards in carbon steel, alloy steel and stainless steel. It is also available in and API standards - see catalogue sheet Fk 0.71GB. Characteristics for the valve type are: Suitable for all usable flange standards Short face-to-face length - invaluable where space is limited Low weight results in low handling costs and ease of installation Low pressure drop and low opening pressure Fully open with water velocity of only 0.6 m/s - without closing spring Excellent tightness, better than demanded in API 98 Rapid response - oblique seat reduces closing travel Can be furnished with auxilliary spring to reduce water hammer in liquid media CE-marked according to Pressure Equipment Directive (PED 97/2/EG) module H, category III. Design The circular wafer body is designed to be clamped between two pipe flanges. A list of the international flange standards to which the valve is adapted is shown on page 8. The valve disc is suspended on two heavy stub shafts with the selected suspension points giving the fastest closing possible. The stub shafts are sealed externally by integrally welded plates. The seat is oblique in order to give a short closing travel and thus a short closing time. NAF-Check can also be supplied with an auxiliary spring. Due to the lightweight disc, the auxiliary spring can shorten closing time further and reduce water hammering to one fourth that obtained using springless valves at quickly returning liquid flow. In order to facilitate installation, valves > are equipped with a lifting eye. An arrow cast into the lifting eye indicates the flow direction. Face-to-Face Length According to EN 8-1, Series 16. Connection NAF-Check is intended for clamping between flanges and fits most pipe flanges in accordance with DIN, and BS - see table on page 8. Test Pressures ( 1) Pressure Class PN *Leakage never exceeds 1 cm /minute - regardless of connection size - for specified test pressure. Test medium is water. Applications NAF-Check can be used in any liquid, gas or vapor which is compatible with the valve itself. We recommend valves with auxiliary spring for use in liquid flow. Limitations: See instructions in tables on page 6. Selection ( 2) NAF * Valve with auxiliary spring open Test pressure bar(e), water* valve closed valve No. PN Material Steel 20* -0 Steel Steel 2660* -0 Steel Alloy steel 2682* -0 Alloy steel Stainless steel 28* -0 Stainless steel Staniless steel 2860* -0 Stainless steel 1

2 Working Pressures and Temperatures ( ) NAF No. PN Max. working pressure, bar(e) at temperatures up to C Temperature range -0 - o C OBS! Flange Pressure and temperature limits. Material Specifications

3 NAF-Check Tilting Disc Check Valves NAF 2X0, 266X0 ( 4) Item Qty Part Material in standard design 1 1 Body - EN EN1.48 / CF8M -0 EN / WCC 2 1 Disc - EN EN1.417 Sealing surfaces -0 Directy machined on body and disc -0 Body: Deposit-welded, haedened stainless steel. Disc: Direct machined 4 2 Stub shafts EN1.21 / ASTMA276 typ Spring EN1.468 / ASTMA typ 6 NAF 26822, 2662 ( ) Item Qty Part Material in standard design 1 1 Body EN1.77 / WC6 2 1 Disc EN1.77 / WC6 Sealing surfaces Body: Deposit-welded, hadened stainless steel. Disc Deposit welded stellite 4 2 Stub shafts EN1.21 / ASTMA276 typ Spring EN1.468 / ASTMA typ 6 NAF 28X0, 286X0 ( 6) Item Qty Part Material in standard design 1 1 Body - EN EN Disc EN / CF8M Sealing surfaces Machined directly inbody and on disc 4 2 Stub shafts EN Spring EN1.468 / ASTMA typ 6

4 Selection of Valve Size and Pressure Drop In pipes with steam or gases (compressible media) it is important to check that the valve is fully open and the disc thus pressed against the stop at all normal operating conditions. This in order to avoid disc flutter giving noise and shorter valve life. The dynamic opening force on the disc depends on density of the medium and flow velocity in the pipe. Use the diagram in fig. 1. Set the value of ρxv 2 on the horizontal axis and check the curves. Depending on installation position, the valve without auxiliary spring is fully open if the value ρxv 2 on the horizontal axis is larger than (point 2-E) in a vertical pipe, or 0 (point 2-C) in a horizontal pipe. Select a smaller size if the valve is not fully open. Valves with auxiliary spring, which we only recommend for use in liquids - at the risk of water hammer - the corresponding values are 8 (point 1-D) and 0 (point 1-B). Read the pressure drop across fully open valve on the vertical axis and at the intersection of the straight line "Fully open valve". The pressure drop is larger if the valve is not fully open (follow resp. line regarding pipe and spring). The curves in fig. 1 represent sizes up to 0.The pressure drop is lower for larger sizes. Reduce the diagram pressure drop values with following factors: - factor factor factor 0.78 With flow rate - in water - known in m /h the pressure drop across the valve can be read directly in the diagram - fig. 2. 4

5 NAF-Check Tilting Disc Check Valves Pressure drop m vp * Select the density for present pressure and temperature before the valve 2 1 0,7 0, 0, 0,2 0,1 0,07 0,0 Vertical pipe with spring without spring Fully open valve Horizontal pipe with spring without spring 0,0 0,02 * 0, ρ x v 2 0,1 0,2 0, 0,4 0, 0,6 0,7 1,0 2,0,0 4,0 v m/s 2 - E 2 - C 1 - D 1 - B for water with ρ = 0 Fig. 1 Example 2 Example 1 Example 1. Water 2. Air Flow velocity 2 m/s Density ρ = 1, kg/m b) Horizontal pipe ρ x v 2 = 0 x 2 2 = 00 Flow velocity1 m/s The valve is not fully open - Pressure drop 0,7 m vp ρ x v 2 = 1, x 1 2 = 1, x 2 = 292 risk of flutter. Select valve with auxiliary a) Vertical pipe the valve is fully Select a smaller valve! spring open. Pressure drop 0,02 m/s (Pressure drop 0,07 m vp)

6 Pressure drop - capacity m vp ,8 0,7 0,6 0, 0,4 0, 0,2 0,1 0,08 0,07 0,06 0,0 0,04 0,0 0, Q m /h water Abb. 2 0, A. Before the valve is fully open, the pressure drop across it exceeds the value shown - see fig. 1. D. Valve fully open - with spring - assisted disc and as fitted in a vertical pipe. B. Valve fully open - with springassisted disc and as fitted in a horizontal pipe. C. Valve fully open - without spring-assistance and as fitted in a horozontal pipe. E. Valve fully open - without springassistance and as fitted in a vertical pipe. Q x ρ other media (ρ in kg/m and Q in m /h) Limitations Caution should be exercised in certain application areas. These are: 1. Small, pulsating gas flows such as are emitted from a piston compressor. The valve selected in such cases shall be small enough to open fully during normal operations, thus preventing flutter. 2. Low-pressure gases. The opening dynamic force is affected by density. Make certain that velocity and density are adequate to open the valve - fig. 1.. Location on suction side of centrifugal pumps. Place the check-valve on the delivery side to avoid starting and cavitaton problems. 4. Pumps in parallel. Make certain that pump characteristic fall the entire flow range. 6

7 NAF-Check Tilting Disc Check Valves Dimensions and Mass NAF Auxiliary spring can be easily replaced or retro-fitted Oblique seat results in short closing swing ( and have straight seats) Figur NAF 220/ /2 2820/ / /0 Installation The NAF-Check valve can be installed in vertical or horizontal pipes. Flow direction in vertical pipes must be upwards. Detailed installation instructions - Fi 0.79A - are supplied with each valve. ( 7) dimensions in mm d d 1 D L L 1 Mass kg NAF 26620/0, 28620/ , , , NAF 220/0, 2820/ ( 8) dimensions in mm d d 1 D L L 1 Mass kg NAF 26822/ * Minimum internal diameter of pipe Ordering Example When ordering, please state the NAF-number, - and valve type, e.g. as follows: NAF 26620,, NAF-Check check valve. 7

8 Connection - Standard Sizes NAF-Check is avaiable to fit the majority of standard flanges. In the tables below we have stated the fitting of connections to different standards. "x" PN PN16 26 DIN PN 264 PN 26 Slip on, BS10 Weld neck, E, F H 10/2, 16/2 /2, /2 BS 44: /, 16/ /, / x x x x x x x x 1 0 PN DIN SS PN PN Slip on, Weld neck lb/sqin 1 to B16.1 BS10 E, F Weld neck BS 44:1969 Slip on 10/2 16/ 2 / 2 10/ 16/ / x x x x - x x x x x - x x x x x x x - x x x x x x x - x x x x - x x x x x x x - x x x x x x x - - ø x x x x x x - - x x x x x x - - x x x indicates that the connection fits. " " indicates that this connection is'nt available to present standard. NAF 26620/0 and 28620/0 ( 9) NAF 220/0 and 2820/0 ( 10) NAF 26822/2 ( 11) PN DIN SS PN PN Slip on,0, 600 Weld neck, 0, 600 BS10 H,J K,R Weld BS 44:1969 neck /2 / 2 / 2 x x x 1 x x x 0 T 0 x x - x "T" indicates that the internal diameter of the pipe flange must be checked by the purchaser. The diameter must not be less than d 1 as shown in the table on page. "ø" indicates use of 29" flanges. " " indicates use of " flanges." " indicates use of 9" flanges. See also Fk 0.71GB, describing NAF-Check according to API 94, B 16, Class -. Slip on / x x x x - x x x - - NAF AB SE Linköping Sweden A Flowserve Company Telephone Facsimile info@naf.se Website: 8 ISO 9001 Certified We reserve the right to design modifications without prior notice