December 11, 2015, WAT051512 Rev. B
Page 4
If the gradient mixer is left attached to the LC system during prolonged shutdowns,
thoroughly flush any halogenated mobile phases and/or aqueous mobile phase
(especially salt buffers) from the gradient mixer and store the gradient mixer in an
organic solvent, such as 100% methanol.
If the gradient mixer is removed from the system and stored, follow the steps
outlined above for prolonged storage then displace all solvent within the unit with an
inert gas (nitrogen flush).
Maintaining the gradient mixer
The gradient mixer requires a minimum of maintenance. Follow these procedures to
ensure maximum efficiency.
To maintain the gradient mixer:
1. Be sure to follow the proper start up and shut down procedures outlined in
“Operating the gradient mixer”
.
2. Check your operating backpressure regularly for increases above normal. This is
often caused by a clogged in-line filter and is easily verified by removing the
column and checking the pressure drop across the in-line filter alone. If the
pressure drop is high, replace the filter inside the assembly as follows:
a. Unscrew the two halves of the in-line filter assembly (plumbed before the
gradient mixer as shown in Figure 1:1
remove the filter.
b. Place a new filter in the assembly and hand tighten.
Note:
If the gradient mixer is the cause of the increase, change the direction of
flow. This should dislodge any foreign matter within the narrow passageways
and correct the pressure problem.
Waters limited product warranty
Waters corporation provides this limited warranty (the Warranty) to protect customers
from nonconformity in the product workmanship or materials. The warranty covers all
new products manufactured by Waters and its subsidiaries.
The warranty is as follows:
Waters warrants that all products sold by them will be of good quality and
workmanship. The products will be fit for their intended purpose(s) when used strictly
in accordance with Waters instructions for use during the applicable warranty period.
Table 1–2:
Replacement parts
Description
Part number
Quantity
Compression screws
WAT025313
2
Ferrules
WAT022330
2
In-line filter element
WAT088084
1
Tee fitting
WAT075215
1
