ASEPTIMIX Agitator Welding Guidelines Version 1.0
Last Update of document 3/6/2014 ASEPCO Corporation 355 Pioneer Way Mountain View, CA 94041 USA Tel: 800.882.3886 or 650.691.9500 Fax: 650.691.9600 www.asepco.com Copyright 2014 ASEPCO Corporation. All rights reserved. ASEPTIMIX is a trademark of ASEPCO. Page 2 of 17
Table of Contents 1. General Information 4 1.2 Warning Designations in this Document 5 1.2 Mixer Warranty 5 1.3 Technical Service 5 1.4 Return Procedure 5 2. Safety 6 2.1 General Warnings for the ASEPTIMIX Mixer 6 3. Welding Checklist for the AMP 7 4. Positioning the AMP 8 4.1 Orientation 8 4.2 Free Distance Between Welds 9 4.3 Location of AMP 9 4.4 Making the Hole for the AMP 10 5. Welding Instructions 12 Step 1: Preparation Before Welding 12 Step 2: INTERNAL Tack Welding of the AMP 12 Step 3: EXTERNAL Tack Welding of the AMP 14 Step 4: Final EXTERNAL Welding of the AMP 15 Step 5: Final INTERNAL Welding of the AMP 16 Step 6: Grinding and Polishing 17 Page 3 of 17
1. General Information The ASEPCO ASEPTIMIX Agitator s assembly mounting post (AMP) is an integrated part of the vessel on which it is mounted (see Figure 1-1). This document describes how to position and weld the AMP into a dished-bottom vessel. Before starting to weld in the AMP, make sure that you have received all necessary material certificates and approvals from ASEPCO. Figure 1-1: ASEPTIMIX AMP and related hardware Page 4 of 17
1.2 Warning Designations in this Document Warnings and prohibitions are marked in this manual with one of symbols shown below. WARNING: Possibility of severe personal injury, loss of life, or equipment damage. FIRE OR HEAT HAZARD: Possibility of severe personal injury, loss of life, or equipment damage associated with extreme heat or fire exposure. 1.2 Mixer Warranty ASEPCO offers a two-year warranty on workmanship for our mixers. Modifying the mixer voids any warranty. 1.3 Technical Service ASEPCO offers comprehensive after-sales service. If any adverse issue (such as material defect or mixer function) with your mixer develops, contact ASEPCO immediately to determine the most effective resolution for the issue. Contact ASEPCO Customer Support at 1-800-882-3886 (info@asepco.com) to order spare parts or to get advice regarding the operation of your ASEPCO ASEPTIMIX mixer. Support is available Monday Friday, from 7 a.m. to 5 p.m. Pacific Time, except for holidays. 1.4 Return Procedure When returning a mixer, contact ASEPCO for an RMA number. Package the mixer carefully to prevent damage in transit. Please label the boxes, packing slips, and all correspondence with the RMA number provided by ASEPCO. Page 5 of 17
2. Safety Anyone who installs or operates this equipment must carefully read and understand this manual before using or installing this equipment. Failure to follow operating and installation instructions could result in operator injury or damage to the equipment. All ASEPCO mixers are supplied as components and must be mounted onto process vessels before use. The mixers must not be modified in any way or run beyond the limits specified in this manual or addendums to this manual. 2.1 General Warnings for the ASEPTIMIX Mixer Be careful to read and follow these warnings. This welding process document must be read carefully and thoroughly understood before the AMP is installed. All warnings must be considered. Neglecting to follow these instructions can result in material damage of the equipment. Local codes and regulations supersede this welding guideline. To avoid burns, stay away from all heated parts as well as the drive unit. Page 6 of 17
3. Welding Checklist for the AMP Complete all of these items prior to welding: Carefully read and understand the welding instructions for ASEPTIMIX AMP. Verify that all necessary material certificates are received from ASEPCO. Ensure that welder is authorized and familiar with this type of welding operation. When welding, follow these safety guidelines: Verify that the location of the AMP and distances between welding joints fulfill pressure the vessel code. Take into consideration orientation for AMP angles (see section 4.1 Orientation). Follow the welding procedure described in this document for positioning of welds with careful attention paid to all warnings. Use heat sinks during the welding process to reduce the risk of warping (strongly recommended). These can be placed on the interior or exterior of the AMP. Cool the weld zone after each weld. The weld should be cool to touch (80 90 F). Page 7 of 17
4. Positioning the AMP 4.1 Orientation The AMP unit comes with either a four-, five-, or six-bolt mounting design, which makes removing and re-installing the drive unit from the AMP relatively easy. When welding in the AMP, ensure that the bolt-hole pattern is in a position where the drive unit and motor can be mounted and dismounted without interfering with vessel legs or other obstructions (see Figure 4-1). We strongly suggest that you leave at least 35 degrees of movement to ensure no interference. Figure 4-1: Bottom view of tank with 4-hole (left), 5-hole (right), and 6-hold (bottom) posts Page 8 of 17
Ensure that the drive unit can be mounted and dismounted without interfering with vessel legs or other obstructions. 4.2 Free Distance Between Welds The minimum free distance between two welds is specific for each pressure vessel code. Check the relevant pressure vessel code for the smallest permissible distance (W) between the weld seam of the AMP and any other weld (Figure 4-2). Figure 4-2: Weld distance 4.3 Location of AMP Locate the AMP in the dished head so that the requirements for the actual pressure vessel code are fulfilled. An AMP that is welded closer to the center of the vessel creates a vortex more easily than an AMP welded closer to the vessel wall. Page 9 of 17
DIM W R1 R2 L A Description Distance from AMP weld seam and any other weld Knuckle radius Vessel head radius Distance from center of vessel to beginning of knuckle radius Distance from center of vessel to center of AMP Use the following formula as a guide for determining the location of the AMP (A): Vessel Diameter A < 40 0.5 x L > 40 0.3 0.5 x L The limitations described in section 4.2 overrule any conflicts with these calculations. 4.4 Making the Hole for the AMP 1. Before making a hole for the AMP, complete all other welding needed on the lower dished head, such as welds required for tank outlet valves, adapter connections for sensors, and sample ports. 2. Using the placement recommendations described in section 4.3, make the hole for the AMP the same diameter as the AMP. Be careful not to make it more than 0.040 inches larger than the AMP OD. Page 10 of 17
3. It is important to minimize the air gap between the AMP and the edge of the hole. To facilitate this, grind the exterior edge of the hole at a 45 angle sloping outward to create a weld groove. Leave a straight edge of no more than 0.060 inches on the inner edge of the tank (see Figure 4-3). Figure 4-3: Hole for AMP and air gap Page 11 of 17
5. Welding Instructions The welding process has several steps. Please follow all welding instructions carefully. The process is designed to provide a durable, leak-proof weld that minimizes warping. During all welding operations, be careful to not overheat the material. We strongly recommend that you use heat sinks during the welding process to reduce the risk of warping. They can be placed on the interior or exterior of the AMP. Step 1: Preparation Before Welding 1. Ensure that the heat number on the AMP matches the AMP material certificate. 2. Set up for the TIG welding method unless this conflicts with the local pressure vessel code. 3. Verify that the proper filler material is being used. Step 2: INTERNAL Tack Welding of the AMP 1. Place the AMP into the predrilled hole so that the inner surface of the dish is 0.050 inches to 0.080 inches below the outermost edge of the AMP (Figure 5-1). Figure 5-1: Weld position Page 12 of 17
2. Tack weld at A and B (see Figure 5-2). Figure 5-2: Internal tack welding locations (shown from inside the vessel head) 3. Check the inner surface of the vessel to ensure the correct insertion depth of the AMP (see Figure 4-4). Make necessary corrections. 4. Tack weld at C and D (see Figure 5-2). Page 13 of 17
Step 3: EXTERNAL Tack Welding of the AMP 1. Start with the dished head turned upside down on a clean working surface and fill it with protective gas (keep the gas flowing during the welding process). Figure 5-3: Internal tack welding locations (shown from inside the vessel head) 2. Tack weld the AMP as follows: a. Start with the first weld group: A then B then C then D per Figure 5-3 and 5-4. These welds should be in the same location as the tack welds performed on the inside of the vessel. b. Follow the numbers 1 through 12 as indicated in Figure 5-4, which shows the positions of four groups of four welds each. Page 14 of 17
Figure 5-4: External tack welding pattern (shown from outside the vessel) Step 4: Final EXTERNAL Welding of the AMP 1. In a clockwise movement from tack to tack and using the appropriate filler material, weld the AMP. Note that the weld progression (shown in Figure 5-5) consists of four groups of four welds. 2. Cool the weld zone with compressed air in between welds until it is no longer hot to the touch (80 90 F). Page 15 of 17
Figure 5-5: Tack to tack external welding pattern 3. Repeat the welding process identified until the weld profile is shaped like a fillet weld with no undercut present. Step 5: Final INTERNAL Welding of the AMP 1. Turn the vessel head over so that you are looking at the inside of the vessel. 2. Fill any imperfections in the weld seam using the appropriate filler material. 3. Cool the weld zone in between welds until it is no longer hot to touch (80 90 F). Page 16 of 17
Step 6: Grinding and Polishing After cooling the assembly, grind and polish the welds to the final finish, as required by the specifications. When polishing the welds, inspect the welds carefully to ensure that full penetration has been achieved. Fix any imperfections. Page 17 of 17