Grundfos · Long-Coupled End Suction Pump
NK
81 US builds: 3 to 200 HP, 25 pump sizes from 015-095 to 080-150, 60 Hz.
3-200 HP Fixed Speed
NEMA Premium ODP Motor
230/460V 3Ph or 460V 3Ph
2-1/2-10 in Suction x 1-1/2-8 in Discharge
ANSI Class 125 Flanges, 174 psi
DOE PEI CL 0.87-0.97
-13 to 248°F Liquid
Cast Iron Housing, Stainless Steel Impeller
Overview
The NK is Grundfos’s single-stage, end suction volute pump in its US Range 6 build: NEMA motor, ANSI Class 125 flanges, assembled in Brookshire, Texas. The pump and its foot-mounted motor sit on a steel C-channel base frame, joined by a flexible coupling. The motor runs at a fixed 1750 RPM for steady-flow duties. Each part number is one pump size with one trimmed impeller and one motor; the table below gives the rated duty point Grundfos publishes for each.
- Stainless steel impeller, hydraulically balanced for low noise and long seal and bearing life
- Silicon carbide / silicon carbide / EPDM shaft seal (BQQE), standard on all N-series pumps
- Foot-mounted volute and back pull-out design for service without breaking the piping
What Ships and What It Needs to Run
Included: the NK pump with its motor, coupling and guard on a steel base frame.
Ships by freight: about 192-1,900 lb by build; plan for a forklift at delivery.
Sized at install: isolating valves, a motor starter with overload protection, and a level foundation.
Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
12-Month Grundfos Warranty
Covered for 12 months from the date of purchase under Grundfos’s published warranty terms.
Specifications
| Pump type |
Single-stage, end suction, long-coupled volute pump, back pull-out, Grundfos Range 6 (NEMA) |
| Motor |
Baldor NEMA Premium ODP motor (IP22), foot-mounted on a steel C-channel base frame |
| Speed |
1750 RPM (4-pole) |
| Power supply |
230/460V 3Ph, 460V 3Ph, 60 Hz |
| Connections |
ANSI B16.5 Class 125 flanges |
| Maximum operating pressure |
174 psi |
| Liquid temperature |
-13 to 248°F with the BQQE seal |
| Pump energy index |
DOE PEI CL 0.87-0.97 by build |
Models & Performance — Will It Do What You Need?
Each line is one pump size at one speed: suction x discharge, motor HP, shut-off head and the largest maximum flow. Open the size that covers your duty point. Each row is one impeller this listing sells, and every figure is the total head in feet the pump adds at that flow. The model number ends in the impeller diameter in inches (020-110/9.92 = 9.92 in).
NK 015-095, 1750 RPM: 2-1/2 x 1-1/2 in, 5-7 1/2 HP, 90-113 ft, 248 GPM
| Impeller |
0 GPM |
125 |
185 |
248 (Max) |
| /9.84 |
113 |
106 |
93 |
74 |
| /8.82 |
90 |
82 |
72 |
— |
NK 020-095, 1750 RPM: 2-1/2 x 2 in, 3-7 1/2 HP, 50-105 ft, 297 GPM
| Impeller |
0 GPM |
150 |
225 |
297 (Max) |
| /9.45 |
105 |
98 |
86 |
70 |
| /8.11 |
76 |
70 |
59 |
— |
| /6.61 |
50 |
45 |
— |
— |
NK 020-110, 1750 RPM: 2-1/2 x 2 in, 5-15 HP, 73-122 ft, 376 GPM
| Impeller |
0 GPM |
190 |
280 |
376 (Max) |
| /10.31 |
122 |
115 |
103 |
87 |
| /9.92 |
114 |
108 |
96 |
— |
| /8.98 |
91 |
86 |
74 |
— |
| /8.11 |
73 |
66 |
— |
— |
NK 020-135, 1750 RPM: 3 x 2 in, 7 1/2-20 HP, 93-180 ft, 403 GPM
| Impeller |
0 GPM |
200 |
300 |
403 (Max) |
| /12.52 |
180 |
174 |
159 |
130 |
| /11.42 |
148 |
141 |
126 |
— |
| /10.16 |
113 |
106 |
— |
— |
| /9.29 |
93 |
85 |
— |
— |
NK 025-070, 1750 RPM: 3 x 2-1/2 in, 3-5 HP, 49-52 ft, 302 GPM
| Impeller |
0 GPM |
150 |
225 |
302 (Max) |
| /6.77 |
52 |
50 |
46 |
37 |
| /6.61 |
49 |
46 |
41 |
— |
NK 025-095, 1750 RPM: 3 x 2-1/2 in, 3-10 HP, 39-98 ft, 427 GPM
| Impeller |
0 GPM |
215 |
320 |
427 (Max) |
| /9.53 |
98 |
94 |
85 |
69 |
| /8.43 |
78 |
74 |
65 |
— |
| /7.17 |
56 |
53 |
46 |
— |
| /5.98 |
39 |
35 |
— |
— |
NK 025-110, 1750 RPM: 3 x 2-1/2 in, 7 1/2-15 HP, 82-141 ft, 479 GPM
| Impeller |
0 GPM |
240 |
360 |
479 (Max) |
| /11.02 |
141 |
130 |
114 |
89 |
| /9.45 |
102 |
92 |
79 |
— |
| /8.58 |
82 |
72 |
56 |
— |
NK 030-070, 1750 RPM: 4 x 3 in, 3-5 HP, 36-51 ft, 470 GPM
| Impeller |
0 GPM |
235 |
350 |
470 (Max) |
| /6.85 |
51 |
48 |
42 |
31 |
| /5.83 |
36 |
32 |
26 |
— |
NK 030-095, 1750 RPM: 4 x 3 in, 5-15 HP, 39-89 ft, 685 GPM
| Impeller |
0 GPM |
340 |
510 |
685 (Max) |
| /8.86 |
89 |
89 |
85 |
76 |
| /7.52 |
63 |
63 |
57 |
— |
| /6.73 |
48 |
47 |
41 |
— |
| /6.10 |
39 |
36 |
28 |
— |
NK 030-135, 1750 RPM: 4 x 3 in, 15-40 HP, 95-198 ft, 832 GPM
| Impeller |
0 GPM |
420 |
620 |
832 (Max) |
| /12.91 |
198 |
191 |
177 |
155 |
| /11.26 |
153 |
145 |
133 |
— |
| /10.63 |
136 |
128 |
114 |
— |
| /9.92 |
118 |
110 |
93 |
— |
| /8.98 |
95 |
86 |
— |
— |
NK 040-070, 1750 RPM: 5 x 4 in, 3-7 1/2 HP, 28-49 ft, 723 GPM
| Impeller |
0 GPM |
360 |
540 |
723 (Max) |
| /6.85 |
49 |
45 |
39 |
27 |
| /6.30 |
41 |
37 |
31 |
— |
| /5.43 |
28 |
22 |
— |
— |
NK 040-095, 1750 RPM: 5 x 4 in, 7 1/2-20 HP, 42-95 ft, 1,098 GPM
| Impeller |
0 GPM |
550 |
820 |
1,098 (Max) |
| /9.37 |
95 |
89 |
77 |
55 |
| /8.35 |
77 |
70 |
59 |
— |
| /7.09 |
53 |
44 |
35 |
— |
| /6.38 |
42 |
33 |
25 |
— |
NK 040-110, 1750 RPM: 5 x 4 in, 15-30 HP, 74-116 ft, 1,058 GPM
| Impeller |
0 GPM |
530 |
790 |
1,058 (Max) |
| /10.08 |
116 |
115 |
107 |
92 |
| /9.45 |
105 |
105 |
97 |
— |
| /8.74 |
89 |
87 |
77 |
— |
| /8.11 |
74 |
71 |
60 |
— |
NK 040-135, 1750 RPM: 5 x 4 in, 20-50 HP, 97-190 ft, 1,107 GPM
| Impeller |
0 GPM |
550 |
830 |
1,107 (Max) |
| /12.83 |
190 |
186 |
169 |
147 |
| /11.81 |
160 |
154 |
138 |
— |
| /10.94 |
136 |
128 |
111 |
— |
| /10.24 |
119 |
110 |
93 |
— |
| /9.29 |
97 |
91 |
— |
— |
NK 040-150, 1750 RPM: 5 x 4 in, 50-100 HP, 156-257 ft, 1,603 GPM
| Impeller |
0 GPM |
800 |
1,200 |
1,603 (Max) |
| /15.20 |
257 |
249 |
221 |
185 |
| /13.86 |
210 |
199 |
173 |
— |
| /12.91 |
180 |
168 |
143 |
— |
| /12.20 |
156 |
146 |
120 |
— |
NK 050-070, 1750 RPM: 6 x 5 in, 5-10 HP, 37-49 ft, 1,003 GPM
| Impeller |
0 GPM |
500 |
750 |
1,003 (Max) |
| /6.93 |
49 |
42 |
36 |
23 |
| /6.61 |
44 |
35 |
29 |
— |
| /6.06 |
37 |
25 |
20 |
— |
NK 050-095, 1750 RPM: 6 x 5 in, 15-30 HP, 55-88 ft, 1,546 GPM
| Impeller |
0 GPM |
770 |
1,150 |
1,546 (Max) |
| /9.13 |
88 |
84 |
76 |
60 |
| /8.74 |
81 |
76 |
68 |
— |
| /8.19 |
69 |
64 |
56 |
— |
| /7.40 |
55 |
47 |
38 |
— |
NK 050-110, 1750 RPM: 6 x 5 in, 20-40 HP, 72-121 ft, 1,669 GPM
| Impeller |
0 GPM |
830 |
1,250 |
1,669 (Max) |
| /10.63 |
121 |
116 |
102 |
75 |
| /9.61 |
98 |
93 |
79 |
— |
| /9.06 |
86 |
80 |
67 |
— |
| /8.35 |
72 |
65 |
50 |
— |
NK 050-135, 1750 RPM: 6 x 5 in, 50-60 HP, 144-164 ft, 1,599 GPM
| Impeller |
0 GPM |
840 |
1,250 |
1,689 (Max) |
| /12.01 |
164 |
160 |
145 |
— |
| /11.30 |
144 |
139 |
122 |
— |
NK 050-150, 1750 RPM: 6 x 5 in, 100 HP, 195-195 ft, 2,346 GPM
| Impeller |
0 GPM |
1,150 |
1,750 |
2,346 (Max) |
| /12.99 |
195 |
187 |
167 |
131 |
NK 060-095, 1750 RPM: 8 x 6 in, 15-40 HP, 47-89 ft, 2,618 GPM
| Impeller |
0 GPM |
1,300 |
1,950 |
2,618 (Max) |
| /9.53 |
89 |
81 |
68 |
41 |
| /8.90 |
75 |
65 |
54 |
— |
| /8.43 |
66 |
53 |
43 |
— |
| /7.95 |
56 |
42 |
33 |
— |
| /7.32 |
47 |
30 |
22 |
— |
NK 060-110, 1750 RPM: 8 x 6 in, 40-60 HP, 94-120 ft, 2,626 GPM
| Impeller |
0 GPM |
1,300 |
1,950 |
2,626 (Max) |
| /10.75 |
120 |
113 |
100 |
75 |
| /10.20 |
108 |
99 |
88 |
— |
| /9.57 |
94 |
84 |
72 |
— |
NK 060-135, 1750 RPM: 8 x 6 in, 75-100 HP, 139-169 ft, 3,068 GPM
| Impeller |
0 GPM |
1,550 |
2,300 |
3,068 (Max) |
| /12.24 |
169 |
159 |
137 |
105 |
| /11.22 |
139 |
127 |
109 |
— |
NK 080-135, 1750 RPM: 10 x 8 in, 60-100 HP, 98-135 ft, 4,596 GPM
| Impeller |
0 GPM |
2,300 |
3,450 |
4,596 (Max) |
| /11.26 |
135 |
115 |
95 |
64 |
| /10.31 |
108 |
84 |
66 |
— |
| /9.84 |
98 |
72 |
56 |
— |
NK 080-150, 1750 RPM: 10 x 8 in, 200 HP, 226-226 ft, 4,045 GPM
| Impeller |
0 GPM |
2,000 |
3,050 |
4,045 (Max) |
| /14.25 |
226 |
222 |
197 |
167 |
Head in feet at the flow in GPM heading each column: 50% and 75% of the largest curve, then its end. Bold = the last column that curve reaches; — = beyond its curve. 1750 RPM curves digitized from the Grundfos Range 6 60 Hz data booklet (Data Sheet tab) and rounded down; NB, NBS and NK share the same hydraulics by pump size. Curves are in the image gallery. PSI = feet ÷ 2.31.
Before You Buy — The Limits That Decide the Fit
| Duty point |
Pick the build whose curve passes through your flow and head; send it to us and we will confirm before you order |
| Liquid |
Clean, thin, non-explosive liquids without solids or fibers: water, water-glycol, cooling and heating water |
| Minimum flow |
At least 10% of the rated flow; never run against a closed valve |
| Priming |
Non-self-priming: fill the pump and suction pipe before starting |
| Power |
230/460V 3Ph, 460V 3Ph |
Applications
HVAC heating and cooling circulation, chilled water and cooling towers, district energy, data center cooling, water supply and pressure boosting, industrial liquid transfer and irrigation.
Materials of Construction
| Pump housing |
Cast iron, ASTM A48 Class 35 |
| Impeller |
Stainless steel, ASTM A351 CF8 |
| Shaft |
Steel / stainless steel, AISI 1045 / 304 |
| Shaft seal |
BQQE: silicon carbide / silicon carbide, EPDM |
From Grundfos Product Center build data.
