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Valves
Stainless Steel Sample Loops
These high quality stainless steel sample loops have burr-free,
square-cut ends to ensure a fush connection to valve ports. The size
designations of loops are nominal. The actual volumes can differ
from the theoretical designations because of the 0.001” (± 0.025 mm)
tolerance of the metal tubing bore.
Accuracy of large metal loops (1.0 mm, 0.040” bore) is about ±5%,
intermediate loops (0.5 mm, 0.020” bore) ±10%, and small loops
(0.2 mm, 0.007” bore) ±30%.
Since both standards and unknowns are usually analyzed using the
same sample loop, knowledge of the actual, accurate volume is rarely
needed. If the sample loop volumemust be known, it is best to calibrate
the loop in place on the valve so the fow passages in the valve are
also taken into account. An alternative to calibration is to use a dual
mode injector and partial-flling method of loading. See the “Sample
Loop Loading” Application Note on page 131.
Model 7725 Injector loops are not interchangeable with loops for the
model 7125. The port angle for the 7725 is 30° whereas the port angle
for the 7125 is 20° requiring the loops to have a different shape.
Model 8125 Micro-Scale Sample Injector requires special loops in the
5.0 µL to 50 µL range. The 8125 sample loops are made with 0.5 mm
(0.020”) OD tubing.
Sample Loops
Part No.
Volume
Tubing
Rheodyne
®
Stainless Steel Loops for MXT715-000
7755-300
5 µL Sample Loop
0.18 mm (0.007”) ID x 1/16” OD
7755-301
10 µL Sample Loop
0.30 mm (0.012”) ID x 1/16” OD
7755-302
20 µL Sample Loop
0.30 mm (0.012”) ID x 1/16” OD
7755-303
50 µL Sample Loop
0.51 mm (0.021”) ID x 1/16” OD
7755-304
100 µL Sample Loop
0.51 mm (0.021”) ID x 1/16” OD
Rheodyne Stainless Steel Loops for 7125, 7010 Injectors
(Do not use for 7725)
1876
10 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
1877
20 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
7020
5 µL Sample Loop
0.18 mm (0.007”) ID x 1/16” OD
7021
10 µL Sample Loop
0.30 mm (0.012”) ID x 1/16” OD
7022
20 µL Sample Loop
0.51 mm (0.020”) ID x 1/16” OD
7023
50 µL Sample Loop
0.51 mm (0.020”) ID x 1/16” OD
7024
100 µL Sample Loop
0.51 mm (0.020”) ID x 1/16” OD
7025
200 µL Sample Loop
0.76 mm (0.030”) ID x 1/16” OD
7026
500 µL Sample Loop
0.76 mm (0.030”) ID x 1/16” OD
7027
1.0 mL Sample Loop
0.76 mm (0.030”) ID x 1/16” OD
7028
2.0 mL Sample Loop
1.0 mm (0.040”) ID x 1/16” OD
7029
5.0 mL Sample Loop
1.0 mm (0.040”) ID x 1/16” OD
Rheodyne Stainless Steel Loops for 3725-038, 3725i-038 Injectors
3065-018
2.0 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
3065-019
5.0 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
3065-023
10 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
3065-025
20 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
Rheodyne Stainless Steel Loops for 7725, 7725i, PR/EV700-100,
PR/EV703-100, MX Module Injectors (Do not use for 7125)
1876
10 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
1877
20 mL Sample Loop
2.0 mm (0.080”) ID x 1/8” OD
7755-020
5 µL Sample Loop
0.18 mm (0.007”) ID x 1/16” OD
7755-021
10 µL Sample Loop
0.30 mm (0.012”) ID x 1/16” OD
7755-022
20 µL Sample Loop
0.30 mm (0.012”) ID x 1/16” OD
7755-023
50 µL Sample Loop
0.51 mm (0.020”) ID x 1/16” OD
7755-024
100 µL Sample Loop
0.51 mm (0.020”) ID x 1/16” OD
7755-025
200 µL Sample Loop
0.76 mm (0.030”) ID x 1/16” OD
7755-026
500 µL Sample Loop
0.76 mm (0.030”) ID x 1/16” OD
7755-027
1.0 mL Sample Loop
0.76 mm (0.030”) ID x 1/16” OD
7755-028
2.0 mL Sample Loop
1.0 mm (0.040”) ID x 1/16” OD
7755-029
5.0 mL Sample Loop
1.0 mm (0.040”) ID x 1/16” OD
Rheodyne Stainless Steel Loops for 8125 Injector
(Use 7755-024 to 7755-029 for volumes > 50 µL)
8020
5 µL Sample Loop
0.20 mm (0.008”) ID x 0.020” OD
8021
10 µL Sample Loop
0.20 mm (0.008”) ID x 0.020” OD
8022
20 µL Sample Loop
0.25 mm (0.010”) ID x 0.020” OD
8023
50 µL Sample Loop
0.30 mm (0.012”) ID x 0.020” OD
8125-084
Ferrules for 0.020” (0.5 mm) Tubing
8125-086
Ferrules for 0.020” (0.5 mm) Tubing, 4-pk
Application Note
How to Properly Install Sample Loops
Stainless Steel
Stainless steel sample loops are supplied with fttings that are not swaged
onto the tube. It is important that the loop be completely bottomed in the
injector port before the ferrule is swaged onto the tube. The depth of the
tubing holes may vary slightly from port to port and from valve to valve. A
ftting made up in one port may leave a small cavity in another port. The
cavity causes high dispersion and peak distortion such as fronting, tailing, or
broadening. It is good practice to label loop ends so they will be replaced
in the same, respective ports that were used in swaging the ferrules. Hint:
swaging ferrules separately on each side, into each respective valve port
makes loop installation easier.
To install the sample loop:
a) Take one end of the loop and place the nut
(1) and ferrule (2) onto the tubing (3) with the
threaded portion of the nut and tapered portion
of the ferrule toward the end. See Figure A.
b) Insert the tubing into port (4). Confrm that
the tubing is bottomed in the valve port as
shown in Figure A.
c) While frmly pressing down on the tubing,
hand-tighten the nut as tight as possible.
d) With the IDEX Wrench (see pages 33 and 140),
designed especially for fttings, tighten one
quarter turn past fnger tight. Remove the loop to
confrm the ferrule is swaged onto the tube.
e) Repeat steps a-d with the other end of the
loop while the swaged end remains outside
the valve port. See Figure B.
f) Reinstall each end of the loop to their
respective ports. See Figure C.
A
C
B
Figure 1 Cut-away view
of stainless steel sample
loop installation
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