Jianghan Petroleum Administration drilling machinery repair

700 kg / cm2 fracturing manifold in two "Swivel joint and elbow Φ45 activities working pressure of 700 kg / cm 2, the test pressure is 900-1000 kg / cm2 at the time of fracturing, quartz carry high pressure sand fracturing fluid flows at high speed Swivel joint bore, so that the bent portion outside the hole wall severe wear, even worn as cast steel blank for manufacturing such activities elbow, can not guarantee the quality. when I plant in the manufacture of such activities in the past elbow, forging a solid rectangular-shaped first and then drilled from both ends of the communication. this structure can not meet the 700 kg / cm 2 fracturing manifold working conditions. now we use the heat and simmer bend - forging process manufacturing activities rough elbows, and to ensure the wall thickness of the wall thickness of the outer part of the activities of the elbow bent more than the inside, after processing pressure test to meet the technical requirements.
High pressure swivel joint rough forging manufacturing process are: car system through holes blank - bore loaded sand - heating - simmer bending, forging - sand - tempered. Now with two "Swivel joint (Fig. 1), for example detailed below.

Figure 12 "Swivel joint rough map
(Figure marked only the main dimensions, the size of the finished size in parentheses)
First, the car system through holes blank
Taking into account the blank-through-hole simmer bend when heated, the bending portion of the outer bi thick to withstand tension while the inner wall thickness thinning thickening, thus requiring the blank into an intermediate section of the eccentric drive (Fig. 2), so that the activities of bending into a simmer lateral head having a sufficient thickness, thereby extending the service life of Swivel joint.

Figure 2 through holes blank
Figure 2 a length of the bent portion may be the length of the arc axis of the hole of the calculation.
Figure 2 eccentric b, according to the principle of constant volume before and after the bend simmer, calculated according to the formula.

Thickness of the curved portion of the inside, because after simmer bend in general can meet the requirements, you can not checking. This eccentric vias blank, we are on a lathe using a car tire eccentric system.
Two, inner bore pack sand
In order to reduce the heat and simmer degree bending deformation parts (variable flat and narrow diameter), the need to fill the hole blank sand, and should be as infill. We used the sand loading apparatus shown in Fig. 5 a larger particle size (diameter about 1-2 mm) of steel with quartz sand (after pre-dried), filled into the hole.

Sand loading device
2.5 tons of extremely heavy items;; 1. 3. Plug welded frame; 4. workpiece; 5 sand; 6 cover.
Before loading the sand cover 6 spot-welded to one end of the first workpiece 4, and then the hole in the workpiece 4 is mounted sand. Sand installed, the plug 3 on the upper end of the workpiece 4, with extremely heavy pre two sand compacted, and finally the plug 3 spot welding on the workpiece 4.
Third, heating
In order to reduce the deformation resistance simmer bend, and the blank is heated to 1000-1100 ℃. We used to burn heating oil forging furnace, billet heating in the furnace should be timely flip, so that uniform heating, and heat through.
Fourth, simmer bending, forging
Since I do not have a dedicated plant simmer bending equipment, so the use of the tool shown in Figure 6 simmer bend.
Tire with a pore size of the inner sleeve 6 with the workpiece size. Heating the blank first inserted through holes good tire inner casing 1 having a hole 6 (this time to pay attention to the direction of alignment eccentric, a large wall thickness at the outer side of the curved portion), then the four bend the plate. After the pull bend, bend the blank parts will appear slightly varying flat phenomenon is illustrated in Figure 7 shows the correction die forging correction on 560 kg of hammer. Whole simmer bend, the calibration process is completed in a fire, with the 90 ° model checking to ensure that the angle at 90 ° ± 8 ° range.

Simmer bending tool
1. mold; 2 fixed plate frame; under 3.560 kg hammer anvil; 4 plates put; 5 piece; 6 inner sleeve
Five, sand and quenched
Chop child with lid and plug blank ends open, pour sand (sand can be reused). Due allowance is not blank, blank so without roughing direct quenching, thus reducing the activity on the elbow when machining fixture times, avoid alignment difficulties. The main problem with this process is that the presence of: 1 with Human pull bend bend blank simmer, labor-intensive, low efficiency; two must find a positive direction Eun eccentric bent.