Document kNzwe6p1R3YBVvLk30KwG0GB

PLAINTIFF'S EXHIBIT INSTRUCTIONS FOR INSTALLATION, OPERATION AND REPAIRING the CONSOLIDATED SAFETY VALVE Types 1411-1415-1419-1426-1431-1515 Service Manual No. 3 1952 Form No. 250-947 A product of W MANNING, MAXWELL & MOORE, INC. STHATFORD CONNECTICUT 'ii.- i I; ''`' ,l ; ' f` ' BIRD 022229 ' INSTRUCTIONS FOR INSTALLATION AND REPAIR OF CONSOLIDATED SAFETY VALVES TYPES 1411-1415-1419-1426-1431-1515 INSTALLATION Safety valves must be connected in a vertical posi tion directly to the boiler or on equal size fittings no longer than the face-to-face dimension of an American Extra Heavy Standard Iron tee. Under no condition should a stop valve or other obstruction be placed between the boiler and the safety valve. Thoroughly clean the inlet of the valve before installation and be sure that the proper gasket is used. Tighten bolts evenly. The valve at all times should be free from external stresses transmitted from the discharge piping. A slip joint should be provided between the safety valve and discharge piping with ample clearance to take care of thermal expansion movements. Figure 3 illus trates a recommended design. The riser pipe should be large enough to accommodate the full capacity of the valve without causing steam to escape by flowing backward through the drip pan. In no case should the pipe connected to the valve be of a smaller size than the valve outlet HYDROSTATIC TESTING Use a test gag as illustrated in Figure 4 or. each valve to hold the feather to the seat when making water pressure tests. Permitting the valve to lift by water pressure only, lifts the feather slightly and may result in leakage caused by foreign matter becoming trapped. In gagging a safety valve, care must be exercised to avoid overstressing the Spindle and damaging the seating surfaces of the Feather and the Seat Bushing. The screw of the gag should be made only "wrist tight" which is sufficient to keep the valve from leak ing when pressure is raised above the popping point. PRESSURE AND BLOW DOWN ADJUSTMENT To change the popping pressure of a valve remove the Top Lever and Cap. (See Figure 1.) Loosen the Lock Nut and turn Compression Screw clockwise to increase pressure or anti-clockwise to decrease pres sure. Tighten Lock Nut and reassemble Cap and Top Lever. Check to see that Top Lever does not bear against the Release Nut when the Drop Lever is positioned over a Yoke rib. About 1/16" clearance between these parts is desirable. Raising the popping pressure will increase the blow down and likewise, lowering the popping pressure will decrease the blow down. To correct or to change the amount of blow down, take out the Ring Pin and, using a screwdriver or other pointed tool, turn the Adjusting Ring which is threaded to the Seat Bushing. Turning the ring to the right raises the Adjusting Ring, thereby increasing the blow down. Turning it to thp left lowers the ring, thereby decreasing the blow down. If a valve is out of control and will not pop, the ring is probably too low. It is possible that the first blow of a safety valve on steam may be a few pounds higher than after the valve is completely heated. The effect is somewhat greater with a superheater valve since the steam temperature is higher. Therefore the valve should be popped a couple of times before adjustments are changed. Caution: The popping point of a superheater valve should not be checked, or set, by readings taken irom a pressure gauge connected to the boiler drum it the boiler is carrying a load because it does not register the pressure drop through the superheater; instead, use a gauge connected to the superheater outlet with proper allowance being made for waterleg between location of gauge with respect to the valve. VALVE DIFFICULTIES Certain troubles may develop through use or dam age to working parts. The most common are simmer ing, leaking, chattering, and hang-up. Simmering is defined as an audible escape of steam as pressure is raised to near the popping point. A slight simmer is not objectionable and only indi cates slight irregularity of the seating surfaces. Larger amounts of simmer indicate seat damage, too wide a seat, or that the Adjusting Ring is too low. Leaking is the constant escape of steam at normal operating pressure below the closing pressure of the valve. It is caused by either damage to the seating surfaces or to foreign matter being trapped. If hand 2 BIRD 022230 lifting, wide open, does not give relief, apply a gag lightly for a few minutes as described under the head ing of Hydrostatic Testing. If leaking continues (with the gag removed,) the valve should be repaired at the first opportunity to prevent serious wire drawing of the seats. Other causes of leakage are interference of the lifting gear such as the Spindle Nut riding on the Forked Lever, distortion of the valve body from uneven tightening of the inlet flange bolts, and im proper installation of the discharge piping so as to introduce undue strain upon the valve. Chattering is a hammering action of a vibratory nature of the Feather on the Seat Bushing and must be stopped immediately or the seats will be ruined. To stop chattering, hold the valve open with the Drop Lever until the steam pressure has been re duced several pounds. Chattering is caused by the valve: (1) not having sufficient blow down; (2) excessive back pressure from undersize discharge piping; (3) insufficient steam flow to the valve. Hang-up occurs upon closing and is defined as leakage from the valve failing to shut off tightly. Too short a blow down or mechanical interference are the two principal causes. Dropping off of the popping point is many times unjustly charged against the spring losing its "tension". Invariably, however, it is caused by damage to the seats from foreign matter, from chatter, or difference in heat distribution between pops. A reasonable wait ing period between pops will give consistent results. DISASSEMBLING VALVES FOR REPAIR 1. Remove Top Lever and Cap (hand lifting mechanism.) 2. Remove cotter key from Spindle on top of Release Nut. 3. Screw Release Nut down until it engages top of Compression Screw, then lift off the Yoke with the Sp:.ndle, Spring, and Feather assembled. This will permit a quick inspection of the seating surfaces of both Feather and Seat Bushing without changing the popping point. If however, further disassembly of the Spindle, Spring, and Spring Washers is anticipated for inspec tion or cleaning purposes, the approximate spring compression can be determined by unscrewing the Compression Screw and counting the number of turns necessary to just relieve the compression. REPAIRING If only very slight imperfections are found on the seating surfaces they can be readily restored by lap ping them together using machine oil mixed with a fine abrasive of about 500 or 600 grain size. Care should be taken to see that the seats as finished are cor rectly located as shown in Figure 8B or in Figure 9B. If more extensive reconditioning is required, the Feather should be machined and the seat of the Bushing restored by lapping with a cast iron lap fitted with suitable handle as shown in Figure 6, or by remachining as shown in Figure 5. In setting-up the Feather for remacbining make certain that the guiding surfaces of the wings are running true at both ends. Carefully follow the dimensions and angles given in Figures 7A or 7B. If a visual inspection of the seat to be remachined reveals that it is of the "STEP" type, then remachine as in Figure 7B. If of the "PLAIN" type, then follow Figure 7A. Take light cuts across the seat and finish as smooth as possible. To remachine the Seat Bushing, it is advisable to leave it assembled within the body and do the work in a lathe or boring mill. The bore of the Bushing and the Yoke guiding surface should be made to run reasonably true. After cutting the angle of the seat to 45, remachine the end of the Bushing in accord ance with Figure 5. After turning to the smoothest possible finish, use the lap to remove all traces of tool marks. GRINDING-IN THE SEATS Grinding-in is the process of smoothing away tool marks and slight irregularities and broadening the seating-surface contact. Figures 8A and 9A illustrate the Feather-to-Bushing contact before grinding-in. Figures 8B and 9B show the contact after grinding-in when the surfaces are rubbed together with machine oil only. A wrench, consisting of threaded shank fitting the thread in the Feather and provided with a tee-handle, should be used for grinding the Feather to the Seat Bushing. The use of grinding compounds containing coarse and hard-grit abrasives such as silicon carbide and aluminum oxide should be avoided because the metals used in the Feathers and Bushings of wing guided valves are relatively soft and stringiness of the seat ing surfaces is likely to result. Ground glass mixed with oil, Mulley (soft grit abrasive) mixed with oil, and mixtures containing abrasives of about 500 to 600 grain are suitable grinding materials. All can be obtained from Manning, Maxwell & Moore, Inc. 3 BIRD 022231 REASSEMBLING The Adjusting Ring should be examined to be sure that it can be rotated freely. To free a tight ring, apply penetrating oil or hot water and then rap with a block of hard wood. After loosening and cleaning the threads, reset the Adjusting Ring to its original position. Lubricate all threads, Spring Washer and Spindle bearings with powdered graphite mixed with pene trating oil. Spindle-point bearing and Feather-pocket bearing must be smooth and clean and be lubricated with graphite. Make sure that the Yoke-to-Body joint surfaces are clean. Tighten stud nuts evenly and securely. Re-establish Spring compression by first turning down the Compression Screw to take out all play and then add the same number of turns that it took to relieve the compression when the valve was dis assembled. In re-assembling the hand lifting gear make sure that the Release Nut clears the top Lever by at least 1/16" when the Drop Lever is positioned over one of the Yoke ribs. TESTING To insure that safety valves are maintained in good working order they should be hand lifted or popped at periodic intervals. It is recommended that the valves be popped just prior to a boiler outage as a check to determine whether repair work or re adjusting is necessary. Valves should not be lifted by hand unless there is sufficient steam pressure in the boiler to blow foreign matter from within the valve. REPLACEMENT PARTS When ordering replacement or spare parts, state serial number, type, size, and set pressure of the valve, and whether used with saturated steam or superheated steam. Refer to Figure 1 for descriptive names of the parts. -RELEASE NUT -SEAL -TOP LEVER PIN -LOCK NUT COMPRESSION ` SCREW -TOP WASHER -BOTTOM WASHER -YOKE RING * ' SEAL WELL) BODY Fig. 1--Nomenclature and Details of Construction (Illustration Shows Type 1415 Consolidated Safety Valve) BIRD 022232 Fig. 2--Detail of Seat and Feather Assembly Fig. 3--Recommended Installation for Discharge or Vent Piping 5 i BIRD 022233 A BIRD 022234 Detail for "Plain Seat" Fig. 8A--"Plain" Seat Before Grinding-in Fig. 8B--"Plain" Seat After Grinding-in Fig. 9A--"Step" Seat Before Grinding-in n 5, Fig. 9B--"Step" Seat . ' After Grinding-in '), ' 1 ` ` V ' ' V . 1 t } BIRD 022235. MEMO FORM NO. 250-9^7 printed in U.S.A.--minden press, n. y.- M69 BIRD 022236