Rotary Gear Pump Type RDBX-RDNX

Description

Handling high volume of viscous liquid at medium pressure is a challenge & calls for expertise. We at DEL have aquired this over last 25 years through in house research & development based on customer feed back & field trials.

The proven range of rotary twin gear pump type 'RDRN' have been modified to achieve high pressure by reducing the bearing span, balancing the hydraulic force & blocking the slippage path but without compromising on the basic features prominent with all ROTODEL rotary pumps viz the compactness, efficiency, reliability & low noise level.

A pair of impeller with herringbone gear fitted on hardened & ground shaft with shaft sleeves in floating design supported on either side on needle/bush bearings located on end covers with ltb. wearing plate packed in between and placed inside close tolerance accurately machined casing with built in pressure relief valve makes the pump. Size 1/2" to 2 1/2" are provided with BSP thread inlet - oulet flange connections & they are available with foot or flange mounting. Size 3" to 6" are foot mounted with inlet-outlet port drilled to ASA-300 class. Type RDBX is a bush bearing version & is offered upto 2 1/2" size.

This pump can also be offered with different MOC viz. CI,CS, Bronze, SS etc. Pump upto 35 bar are also offered in this series by further reducing the bearing span. The flange type pump coupled with flange type electric motor is offered in horizontal as well as vertical construction.

Dimension

Pump Motor Coding
Sign # Indicates Pump Size 5-short, 6-medium, 7-long
Sign @ Indicates Pump Type 6-RDBX, 7-RDNX

Model 'PQ' BSP Size	Dimensions																							Weight Bp-cou pump Bp-cou in Kg	Product Code
	Overall								Mounting										Shaft		Flange				Pump
	A1	J A	H2	L1	L2	H3	A2 F1 H7	A3 F3 H8	B1 B S	C1 C S1	E2 E1 E	H5 F L	H6 H I	H1	H4	M1	N1	R1 T T1	ØD P Q	K L	ØD1 G M	ØD1 N	ØD3 R
50 SML 1/2"	455 505 522	139 206	235 251 225	425 450 475	140 150 180	143 153 162	196 112 175	460 173 180	125 119 8.5	75 40 15	123 133 58	100 100 112	89 71 60	115 124 134	104 113 123	370 405 430	112 112 140	04 15 40	11.5 04 13	22 25	8 Sq 65 M8	66 66.6	52 04	7.0 6.00 7.50	9D20#@ 9D20#@ 9D20#@
100 SML 1"	520 560 599	151 299	251 225 279	500 525 550	170 180 200	155 165 174	209 112 200	508 203 220	155 125 8.5	85 45 15	131 143 69	120 120 112	104 80 64	124 134 144	108 118 128	445 480 505	135 140 160	04 15 40	15 05 17	25 30	10 Sq 70 M8	83 73	68 04	10.15 11.00 13.0	9F20#@ 9F20#@ 9F20#@
125 SML 1.1/4"	591 630 658	185 250	235 289 323	550 600 600	180 200 230	189 195 211	236 141 220	610 245 220	190 155 10	110 50 15	153 168 81	120 135 141	100 90 70	144 154 166	124 134 146	495 545 545	140 160 190	04 15 50	21 06 23.5	30 40	10 Sq 80 M10	105 85	85 04	12.00 14.50 15.50	9H20#@ 9H20#@ 9H20#@
150 SML 1.1/2"	673 700 764	205 293	289 321 362	625 650 700	200 230 250	207 220 241	278 153 255	677 265 270	230 170 12	130 55 15	180 195 95	145 145 153	123 100 78	154 166 186	132 144 164	570 595 645	160 190 216	04 20 50	24 08 27	40 50	14 Sq 100 M12	125 106	100 04	15.00 24.00 18.75	9J20#@ 9J20#@ 9J20#@
200 SML 2"	746 850 950	234 339	338 377 435	700 825 900	230 250 285	238 258 286	338 173 315	762 285 340	290 200 12	180 70 19	222 223 94	190 165 173	164 112 86	181 205 229	155 175 203	630 755 830	190 216 230	04 20 65	27 08 30	40 55	14 Sq 120 M12	140 127	115 04	18.00 35.00 21.00	9K20#@ 9K20#@ 9K20#@
250 SML 2.1/2"	850 990 1030	261 375	287 445 445	800 900 950	260 315 315	266 294 294	355 173 320	882 325 340	290 225 15	180 80 19	223 250 104	190 190 173	161 132 103	211 239 239	182 210 210	550 650 700	200 254 254	04 25 75	32 10 35	50 60	14 Sq 135 M14	152 149	125 04	19.00 55.00 23.00	9L20#@ 9L20#@ 9L20#@
300 SML 3"	1165 1165 1235	338 436	568 568 616	1150 1150 1200	330 330 355	342 342 362	205		180 19	90 19	289 244	280 205	180 146	284 284 304	250 250 270	850 850 900	279 279 318	04 25 100	37 10 40	55 65	210 22	168	08	33.00 73.00 37.00	9M20#@ 9M20#@ 9M20#@
400 SML 4"	1285 1330 1360	375 487	616 666 666	1300 1400 1400	370 406 406	379 404 404	230		180 19	130 22	323 258	300 230	200 160	304 329 329	264 289 289	900 900 900	318 356 356	04 28 100	47 14 50.5	70 80	254 22	200	08	52.00 92.00 58.00	9N20#@ 9N20#@ 9N20#@
500 SML 5"	1405 1495 1590	420 533	691 794 854	1450 1550 1600	430 470 520	424 449 479	230		200 22	150 22	346 271	340 230	225 179	354 379 409	308 333 363	1050 1050 1150	356 406 457	04 28 150	52 16 56	75 85	279 22	235	08	52.00 142.00 76.00	9P20#@ 9P20#@ 9P20#@
600 SML 6"	1510 1610 1610	467 550	819 879 879	1650 1700 1700	470 520 520	471 501 501	245		215 22	170 22	358 293	345 245	250 200	404 434 434	354 384 384	1150 1150 1150	406 457 457	04 28 150	57 16 61	80 95	317 22	270	12	78.00 173.00 85.00	9R20#@ 9R20#@ 9R20#@

Pump Operation & Performance Characteristics

Gear pump is the most versatile rotary positive displacement pump & it scores over other types of Pd pumps viz. Screw, Vane, Lobe, Tracoidal, Radial piston etc. & therefore it is used for the widest range of application i.e. loading-unloading, transfer, fuel pressurizing, hydraulic, lubrication in IC engines, Polymers metering applications etc. Gear pump can develop high pressure uo tp 210 bar in same configuration simply by tightening the working clearances & improving the workmanship, whereas in screw pump the thread length is needed to increase making the pump bulky & difficult to manufacture. In gear pump each tooth gap contributes to the capacity while in screw pump only one pitch length contributes to the capacity thus gear pumps are always cpmpact & efficient. The capacity of the pump varies directly with speed but remain constant against pressure, however some liquid always by-passes to suction due to running clearance between the casing & impeller causing slip which depends upon the differential pressure, viscosity of the liquid & the workmanship. Gear pumps are capable of handling liquids of any viscosity, th slip reduces with increse in viscocity but the frictional power increses. Though the pump has a self priming capability some net positive suction head(NPSH) is always required to avoid cavitation, this again depends on the viscosity of the liquid to be pumped & the pumping speed.

Internal power losses

In rotary gear pumps are of two types.The mechanical loss is the power required to overcome friction drag of all the moving part within the pump while viscous loss is power loss due to fluid viscous drag & shearing action of the fluid, this can be calculated from the graph shown here.

Horse power calculation

The bhp required to drive a rotary pump is sum of the theoretical HP & internal losses. The former is the actual work done in moving the fluid from inlet pressure condition to outlet pressure condition & is product of constant C=0.037, Capacity in M3/hr. & Pressure in Kg/CM2 or Constant c-2.3, Capacity in GPM & Pressure in PSI.

Gear Pump Selection & uses

RDBX/NX series pump are medium pressure pumps designed for viscous pressure application up to 21 bar. The bush bearing version type RDBX is used for clean or dirty viscous & semi viscous liquid where the shaft surface speed is less. Pump upto 2^1/2" size can be run at 1440 RPM & for higher size the speed should be reduced to 960 RPM or lower. The self-lubricated needle roller bearing type can be used for clear viscous liquid & can be run at 1440 RPM for all the sizes. This pump are ideally suited for fuel pressuring, hydraulic, medium pressure lubrication & transfer applications.

Inspection & testing

All pumps are assembled after due inspection of each & every parts & than they are tested for duty parameters in accordance with API-676 & JIS-B 8312-1976. Third party inspection are also offered, we are approved by following consultants & inspection agencies.

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