GK Packing System Welding Instructions

Transcription

1 GK Packing System Welding Instructions Roxtec GmbH Neuer Höltigbaum 1-3, Hamburg GERMANY Tel +49 (040) , Fax +49 (040)

2 Welding instructions Page 2/18 Welding instructions for GK packing system Foreword: The GK packing system is a safety-related component in shipbuilding. This safety system is of decisive importance on board a ship. For this reason, all necessary tests according to the latest IMO resolution A.754(18) have been carried out on the GK packing system and successfully passed. In the event of a fire, a collision, or if a leaking medium has to be held back, you will be dependent on the reliable sealing off of compartments for the protection not only of the life and health of persons on board but also for preventing greater damage to the ship itself or even its loss. Only when all work on or with the GK packing system has been carried out with care can the high expectations be satisfied which are placed on the packing system with regard to fire resistance, water- and gas-tightness. All of the information which follows is intended as recommendations which the person carrying out the work should check for their appropriateness in the individual case.

3 Welding instructions Page 3/18 Table of contents Section Page: Foreword 2 Table of contents 3 Scope of validity 4 Types of frames 4 1. Welding method Design 1.2 Welding current 1.3 Welding materials Stick electrode Welding wire Shielding gases Cut-out General information 2.2 Size of the cut-out 2.3 Cut edge of the cut-out 2.4 Shape of the cut-out Fitting the frame into bulkhead or deck Tacking the frame Number and position of tacks Welding the frame Checking the welding Checking dimensional tolerances Finishing 6.1 Finishing aluminium structures 18 18

4 Welding instructions Page 4/18 Welding instructions Scope of validity: GK packing system (frame): Single frames and group frames made of - S 235 JR / (St37-2) - S 355 J2G3 / (ST52-3N) to be welded into suitable / compatible steel plates. In addition frames made of aluminium AlMg3, mat. no.: , EN AW5754 for welding into aluminium panels made of compatible aluminium. (As regards other materials please consult ROXTEC-Hamburg) Types of frame: SPK/SPR-60 sizes 2 to 8 SPK/SPR sizes 2 to 8: single and group frames SPK-S30 sizes 2 to 8: single and group frames SPK-S50 sizes 2 to 8: single and group frames SPKh-120/180 sizes 2 to 8 RM connection piece sizes 50 to 200 Information about other types of frame or materials / material combinations may be obtained from: ROXTEC GmbH Neuer Höltigbaum Hamburg Tel: Fax: /51 info@de.roxtec.com Internet: (

5 Welding instructions Page 5/18 1. Welding method A suitable welding method should be used for welding GK single and group frames. In principle there is no different in the welding method between frames without a flange (SPK, SPR) and frames with a flange (SPK-F, SPR-F). 1.1 Design The connection between the frame and the plate takes the form of a single or a double fillet weld (depending on design requirements). Fig. 1.1 Weld details Minimum and maximum thickness of fillet weld a Table 1.1 Fillet weld thickness a Plate thickness t amax [mm] amin [mm]

6 Welding instructions Page 6/ Welding current An amperage should be selected which will ensure sufficient fusing of the base material. In addition, it should be selected such that there is as little heat input as possible in order to avoid unnecessary thermal stress and deformation. 1.3 Welding materials Stick electrode With steel structures One suitable stick electrode is: Type E 425 B 32 H5 * DIN 1912 Key: E 425 B 32 H5 H2 content 5 ml / 100 g weld metal PA and PB weld position type of current: AC/DC covering: basic (rebaking at 300 C; 2 h) minimum impact energy: 47 J at -50 C tensile strength: Rm 420 N/mm² manual arc welding or Type E 4343 RR (B)7 * DIN 1912 Key: E 4343 RR(B) 7 covering: thick rutile basic minimum impact energy: 47 J at -20 C minimum impact energy: 28 J at -30 C tensile strength: Rm 430 N/mm² manual arc welding

7 Welding instructions Page 7/ Welding wire With steel structures I. A suitable type of welding wire (MAG welding) is: (1) Type EMK 6D; 1.2 mm; material no.: * DIN 8559 SG 2 or (2) Type SG3 C Y * Key: SG3 C Y minimum impact energy: 47 J at -20 C minimum impact energy: 28 J at -30 C Rm = N/mm² RP = 460 N/mm² shielding gas CO 2. mechanical quality class 3 With aluminium structures II. A suitable type of welding wire (MIG welding) is: AlMg 5; dia. 1.2 mm * The wire feed should be adapted to the conditions prevailing Shielding gases With steel structures I. A suitable type of shielding gas for welding (MAG) is: For (1) M 2.1 (Corgon 18) shielding gas DIN M21 * For (2) C1 (carbon acid) shielding gas DIN C1 * Consumption of shielding gas is given as approx. 15 l/min. * With aluminium structures II. A suitable type of shielding gas for welding (MIG) is: Argon 4.6 * * All data are recommendations whose suitability should be verified in the individual case by the company carrying out the work.

8 Welding instructions Page 8/18 2. Cut-out 2.1 General information The location of the cut-out for the GK clamping frames should be chosen carefully. The cut-out should be laid out such that the cables, bundled tubing and pipes to be routed straight through the packing frame. In particular the position of the cable racks in front of the frame should be taken into consideration. The cables and pipes should have a bending radius R2 which in area A (see Fig. 2.1) allows the cables or pipes to be routed at right-angles in parallel through the packing frame. Fig. 2.1 Determining the position of the cut-out

9 Welding instructions Page 9/18 Furthermore, it should be ensured that the frames have sufficient clearance from deckheads, adjacent bulkheads, HP profiles or other components. A minimum distance of 25 mm is recommended. Type SPK (see Fig. 2.2) Fig. 2.2 Minimum distances with frames of type SPK The frame can also be mounted flush to the bulkhead or deck on one side and there welded with a I-weld seam. Type SPR (see Fig. 2.3) Caution! With frames of type SPR it is also important to ensure that the pressure bolt can be operated. The threaded hole should also be protected against welding residues during welding-in. The maximum possible plate thickness into which a frame of this type can be welded is 8 mm. If plates are thicker a type SPR frame with additional depth should be used.

10 Welding instructions Page 10/18 Fig. 2.3 Minimum distances with frames of type SPR Type RM sleeve (see Fig. 2.4) Fig. 2.4 Minimum distances with frames of type RM sleeve The frame can also be mounted flush to the bulkhead or deck on one side and there welded with a I-weld seam. If cables and pipes are not routed at right angles through deck or bulkhead it is possible to fit the GK frame at an angle in the opening. Here it should be noted that the cut-out dimensions become larger.

11 Welding instructions Page 11/18 Fig. 2.5 Fig. 2.6 GK frame at GK frame at an angle up to 5.4 an angle up to 28.35

12 Welding instructions Page 12/ Size of the cut-out Type SPK frame: The size of the cut-out should be such that an air gap not exceeding 2 mm runs all the way round the GK frame which is to be used. In each case the dimension Z = 2-4 mm should be added to the width and height of the packing frame to give the cut-out dimensions. Alternatively, in aluminium structures the air gap will not exceed 1 mm. In each case the dimension Z = 1-2 mm should be added to the width and height of the packing frame to give the cut-out dimensions. Fig. 2.7 Size of the cut-out To prevent cracks from forming the corners of the cut-out should always be rounded. Table 2.1 in Section 2.3 gives the radii for the individual types. Type Rm sleeve: The size of the cut-out for a sleeve should be such that an air gap not exceeding 2 mm runs all the way round the GK sleeve which is to be used. In each case the dimension Z = 1-2 mm should be added to the external diameter of the pipe to give the cut-out dimensions.

13 Welding instructions Page 13/ Cut edge of the cut-out A cut-out of sufficient size should be created in the plate for mounting GK single or group frames. The cut edges should be vertical (90 ) to the surface of the plate. Fig. 2.8 Cut edge of the cut-out The cut edges must be smooth and without burr in order to prevent problems in the weld seam. 2.4 Shape of the cut-out The outline of the cut-out should have rounded corners. The straight cut edges of the openings must be parallel and at right angles to each other.

14 Welding instructions Page 14/18 Radii for the most important types of frame: Table 2.1 Cut-out radii GK frame types: SPK-60 sizes 2 to 8 R = 12 mm SPK/SPR sizes 2 to 8: single and group frames R = 12 mm SPK-S30 sizes 2 to 8: single and group frames R = 32 mm SPK-S50 sizes 2 to 8: single and group frames R = 52 mm SPKh-120 sizes 2 to 8 R = 72 mm SPKh-180 sizes 2 to 8 R = 102 mm 3. Fitting the frame into bulkhead or deck The GK frame can be installed in any position. They can be installed anywhere space permits and the minimum clearances are observed (see Section 2.1). Fig. 3.1 The GK frame can be installed in any position.

15 Welding instructions Page 15/18 4. Tacking the frames Before being tacked, the frame should be fixed in its installation position such that a constant air gap runs around the entire frame. Tacking should ensure that welding is as distortion-free as possible. 4.1 Number and position of tacks Tacking should fix the frame in its ideal position. Tacking points should be located as shown in Fig DIN EN should be taken into account when laying out the weld seams. Unnecessary tacks should be avoided if a good weld seam is to be achieved. Fig. 4.1 Location and number of tacking points The air gap should not be larger as otherwise the deformation expected after the frame is welded in will exceed permitted values (see Section 5.1.2). In all cases tacking should be only from one side since every tack disturbs the structure in the weld seam and incomplete weld fusion may occur.

16 Welding instructions Page 16/18 5. Welding the frames Welding-in is done in several steps (see Fig. 5.1) in order to achieve an even input of heat. Welding is continued at the opposite position. Under no circumstances should welding-in be done in just one single operation. This would result in impermissible deformations of the frame which would endanger the impermeability of the packed opening. Fig. 5.1 Welding sequence - if welding is required on both sides, welding can be done in fewer steps on the second side.

17 Welding instructions Page 17/ Checking the welding No breaks are permitted in the weld seams, weld starting points must be carefully executed and must be impermeable without any gaps so that the packing frame is watertight and gastight. 5.2 Checking dimensional tolerances After welding-in and after cooling, the internal dimensions of the frame should be checked: Table 5.1 Maximum values of the internal dimensions GK type D H [mm] [mm] SPK-/SPR SPK/SPR SPK-S30/S SPKh SPKh These values have a tolerance of ± 1.0 mm. Fig. 5.2 Designation of internal dimensions In the event of a deviation from these values, please contact ROXTEC Hamburg.

18 Welding instructions Page 18/18 6. Finishing The weld seams must be cleared of welding residues. 6.1 Finishing steel structures Any paint residues (burnt paint) caused by the welding must be completely removed from the inner surfaces of the frame. Fresh corrosion protection is absolutely essential! (Surface quality as at delivery according to DIN : 3F99) Primer coating: -Celerol reaction primer zinc chromate-free settings: oxide red Coating thickness 20 to 25 µm. - SigmaWeld (after consultation) 6.1 Finishing aluminium structures Fresh corrosion protection is not necessary.