DE10358646A1 - Valve assembly for mixing a multi-component paint and associated operating method - Google Patents

Abstract

The valve arrangement (2) for the producing of a multi-component lacquer has a base lacquer feed line (3), an accelerator feed line (9), and an output line (5) for the delivery of the mixed lacquer. A controllable shut-off valve (15) is installed downstream behind a valve (10) installed in the accelerator feed line. A first flushing medium feed line (19) runs into a pipe section downstream of the shut-off valve, and a second flushing medium line (24) runs into a pipe section between the accelerator valve and shut-of valve. Independent claims are also included for the following: (A) a rotating sprayer with an integrated valve arrangement; (B) a lacquering machine and especially a robot, incorporating a rotating sprayer; and (C) an operating method for a valve arrangement for the forming of a multi-component lacquer, and especially a water based lacquer.

Description

The The invention relates to a valve arrangement for producing a multicomponent varnish, in particular in the form of a mixer for producing a multicomponent water-based paint, according to the generic term of claim 1 and an operating method for such a valve arrangement according to the generic term of claim 12.

It is known in painting technology for painting parts, such as For example, automotive body panels, multi-component paints to be used, which are mixed from a base varnish and a hardener. In such Multicomponent lacquers the base coat can be either solvent-based or water-based based, being aqueous Multi-component paints offer better environmental compatibility. In both make is the hardener however conventional and based on a solvent base.

Out WO 97/00731 is a valve assembly for mixing such Multi-component paint known, for example, on the arm of a painting robot can be arranged and supplies the multi-component paint to a sprayer, which also attached to the arm of the painting robot. This known valve arrangement has a hardener supply line and a stem paint feed line on, which open into a common output line, wherein in the hardener supply line and arranged in each case a controllable valve in the base paint feed line is. About that In addition, the known valve arrangement has a purge line on that over a flush valve also in the common output line of the valve assembly empties.

During the Painting operation are the two controllable valves in the hardener supply line and opened in the base paint feed line, whereas the flushing valve is closed, so that the stem paint in the common output line with the hardener mixes and forms the multicomponent varnish.

to flush and with a color change, the two controllable valves in the hardener supply line and the stem paint supply line closed, while the flush valve open is followed by a water rinse is introduced into the valve assembly and the common output line as well as the downstream behind the hardener valve or the Stammlack valve located pipe sections of the hardener supply line and the stem paint supply line cleans. In this flushing process will alternately water rinse and pulse air initiated.

Problematic Here is the fact that in multi-component paints with a based on water-based base coat an aqueous detergent must be used, a satisfactory flushing effect to reach. This is problematic because of a watery dish soap with the solvent-based based conventional hardeners (e.g. Isocyanate) reacts chemically, which can lead to curing. In extreme cases can this chemical reaction between the conventional hardener and the water detergent cause that in the hardener supply line arranged valve as well as other valves and line sections of the Valve assembly are blocked, resulting in irreversible damage is.

One Another problem with known valve assemblies follows from use so-called pulsed air blown for cleaning in the valve assembly becomes. This is problematic because the pulse air is also humidity contains the solvent-based based hardener reacts chemically, which also leads to a curing and to a corresponding irreversible damage can lead.

Further may also be from the environment (e.g., from the paint booth, over the Nozzle or over one Hose) humidity in the valve assembly and penetrate there the above-described chemical reaction with the Solvent-based based hardener trigger, especially for a longer one Business interruption can lead to irreversible damage.

Of the The invention is therefore based on the object described above to improve known valve arrangement in that a chemical Reaction of the solvent-based based hardener with moisture from the water rinse, the pulse air or the environment as much as possible is prevented.

These Task is, starting from the known previously described Valve arrangement according to the preamble of claim 1, by the characterizing features of the claim 1 and - regarding a corresponding operating procedure - by the features of the claim 12 solved.

The invention includes the general technical teaching when flushing with a water rinse and / or blowing in moisture-containing pulse air and / or at a longer shutdown the hardener valve by a shut-off valve to a contact between the hardener and in the water rinse, the Pulsed air or the ambient air contained moisture ver prevent. By this foreclosure is advantageously prevented that based on Lösemit telbasis hardening agent (eg isocyanate) cures by contact with moisture, which would lead to irreversible damage.

Preferably is therefore downstream behind the hardener valve a controllable shut-off valve arranged to seal off the hardener valve, wherein the shut-off valve is preferably arranged in the hardener supply line. The term used here a hardener supply line includes here preferably, the entire line area for the supply of the curing agent upstream the estuary the stem paint supply line. The hardener supply line so it is not limited to the line area upstream the shut-off valve or even upstream of the hardener valve lies.

Farther has the valve arrangement according to the invention preferably a detergent supply line, the downstream opens behind the shut-off valve in the output line. at a use of the valve arrangement according to the invention for mixing a Multi-component water-based paint becomes a water scavenger via this flushing agent supply line supplied the shut-off valve during the rinsing process is closed to contact the water scavenger with the hardener prevent. Furthermore can over this detergent supply line pulse air are also blown in to clean the valve arrangement, the shut-off valve during the blowing is also closed to a contact between the air humidity contained in the pulse air and the hardener prevent. For blowing in the pulse air, however, may alternatively a separate pulse air supply line may be provided, the downstream downstream opens the shut-off valve in the output line.

It However, there is also the alternative, the water scavenger on the Supply base paint feed line. Here, the water scavenger from an upstream color changer, for example, at a Color change over fed to the base paint feed line become. Again this can be over the base paint feed line alternately initiated rinse aid and pulse air become.

Furthermore has the valve arrangement according to the invention preferably a further detergent supply line on that in a line section between the hardener valve and opens the shut-off valve. When using the valve arrangement according to the invention for mixing of a water-based paint can over this detergent supply line an additional detergent supplied which is based on solvents and / or on the hardener is tuned and therefore does not react with the hardener. This additional dish soap Can be used to remove moisture during a rinse to remove the valve assembly.

It but it is also possible that the line section between the hardener valve and the shut-off valve with the solvent-based based detergent is flooded. This is especially true for a longer business interruption advantageous because the solvent-containing dish soap then as a barrier medium prevents the humidity with the Harder slowly responding.

Also about this additional Detergent supply Pulsed air can be blown into the valve arrangement according to the invention become. However, it is also possible that for blowing the Pulse air another additional Pulsed air supply line is provided in the line section between the hardener valve and opens the shut-off valve. When using a conventional hardener (e.g., isocyanate) however over the extra Detergent supply preferably no pulse air injected, since the hardener with the chemically react in the pulse air containing moisture could, something to harden of the hardener to lead can.

Between the hardener valve and the shut-off valve is preferably arranged a chamber which during a business interruption with the solvent-based detergent can be flooded, so while the interruption of operation on the hardener valve always solvent-containing dish soap as a barrier medium is applied, whereby hardening of the hardener is prevented. The Chamber between the hardener valve and the shut-off valve, for example, by a hose or a hose section are formed.

During the normal painting operation, the shut-off valve is opened, so that the hardener goes through the also open Hardener valve and enter the shut-off valve in the common output line can to get there with the stem paint to the multi-component paint to mix.

at shorter Downtime can then be a normal flushing process by the water detergent or pulse air downstream is introduced behind the shut-off valve, wherein the hardener valve, the Stammlack valve and the shut-off valve is closed. By the Closed shut-off valve prevents this, the water scavenger in contact with the hardener device.

In the event of a prolonged interruption of operation, after this rinsing with the aqueous rinsing agent, an additional rinsing process is preferably carried out in order to prevent clumping which may occur due to the chemical reaction between the aqueous rinsing agent and the hardener. This is done before Preferably, a conventional, solvent-containing detergent introduced into the valve assembly, wherein the introduction is preferably carried out between the hardener valve and the shut-off valve. Here, the hardener valve and the stem paint valve are closed while the shut-off valve is open. On the one hand, residues of the hardener are rinsed out by this rinsing so that later hardenings during the interruption of operation are prevented. On the other hand, residual moisture is removed by this rinsing, which also counteracts hardening of the hardener. After this additional rinsing operation, the shut-off valve is then preferably closed, so that the line region between the hardener valve and the shut-off valve during the stoppage of operation preferably remains filled with the solvent-containing rinsing agent to prevent clumping during the stoppage. Here, the solvent-containing detergent acts as a barrier medium, which prevents hardening of the hardener.

The inventive valve assembly has So preferably two detergent supply lines, wherein the one rinsing agent supply line preferably an aqueous one dish soap supplies and preferably downstream behind the shut-off valve opens into the common outlet line, while the other Detergent supply preferably an anhydrous, solvent-containing dish soap supplies and preferably in the conduit section between the hardener valve and opens the shut-off valve.

Furthermore can the valve arrangement according to the invention also a return line have, which branches off from the base paint feed line and at a Color change a pressing and free rinsing the Stammlack supply line allows. In this context, it should be mentioned that to the base paint supply line upstream Before the valve assembly, a color changer may be connected, the from several available standing Stammlacken the Stammlack of the desired color selects and the valve assembly supplies.

Farther can also contact the hardener supply line Hardener changer connected be who supplies one of several different hardeners.

Preferably are the hardener valve, the stem paint valve and the flushing valves in the valve arrangement according to the invention integrated and part of it. However, the invention also includes such embodiments, where these valves are designed as separate components and the valve arrangement according to the invention upstream.

Further is to mention that the invention is not limited to the valve arrangement described above limited but includes a corresponding operating procedure, in which the common output line for the multi-component paint separated from the hardener supply line is flushable.

Preferably are the separately rinsable line sections of Hardener supply line on the one hand and the output line and / or the base paint feed line on the other hand rinsed here with different detergents. there becomes a conditioner the output line and / or the base paint feed line preferably a water-containing detergent used if the basecoat is based on water. To rinse the Hardener supply line and / or for flooding the line section between the hardener valve and the shut-off valve On the other hand, it is preferable to use an anhydrous, solvent-containing rinse used to form a chemical reaction between the solvent-based based hardener (e.g., isocyanate) and the rinse prevent this, as this could lead to irreversible damage.

Other advantageous developments of the invention are characterized in the subclaims or will be discussed below together with the description of the preferred Embodiments of the Invention with reference to the figures explained. Show it:

1a a schematic representation of a valve assembly according to the invention for the production of a multi-component water-based paint,

1b a simplified cross-sectional view of a rotary atomizer with the valve assembly according to 1a .

2a a schematic representation of an alternative embodiment of a valve assembly according to the invention and

2 B a simplified cross-sectional view of the valve assembly according to 2a ,

The cross-sectional view in 1b shows a rotary atomizer 1 , which is largely conventional, so that in the following no detailed description of the rotary atomizer 1 takes place and only the features essential to the invention are described. The front part of the rotary atomizer 1 is shown hatched for simplicity, not to distract from the essential details of the invention. Regarding the details of the conventional construction of the rotary atomizer 1 becomes an example DE 93 21 294 U1 and DE 43 06 800 A1 verwie whose content is to be fully attributed to the present description.

The rotary atomizer 1 is used for coating parts, such as motor vehicle body parts, with a multi-component water-based paint, which consists of a hardener H and a parent lacquer SL, wherein the curing agent H in an in 1a schematically illustrated valve assembly 2 mixed with the base varnish SL.

For supplying the parent lacquer SL, the valve assembly 2 a stem paint supply line 3 on, from the left in the drawing located on the end face of the valve assembly 2 goes out and over a controllable Stammlack valve 4 in a common output line 5 for the hardener H and the base varnish SL flows, the master varnish valve 4 from a compressed air actuated actuator 6 and a slidably mounted valve needle 7 consists. In its lower stop position blocked the valve needle 7 the transition from the hardener supply line 3 in the common output line 5 , while the transition in raised position of the valve needle 7 is released. The activation of the actuator 6 of the hardener valve 4 takes place via a compressed air control line 8th , which also from the left in the drawing located on the end face of the valve assembly 2 goes out and at the actor 6 ends.

For supplying the hardener H, the valve assembly 2 a corresponding hardener supply line 9 on, which also from the left in the drawing end face of the valve assembly 2 goes out and over a controllable hardener valve 10 in a chamber 11 or a corresponding line volume opens, wherein the hardener valve 10 from a pneumatically actuated actuator 12 and one of the actor 12 driven and displaceably mounted valve needle 13 consists. In its lower stop position, the valve needle blocks the transition from the hardener supply line 9 in the chamber 11 , so no hardener H in the chamber 11 can penetrate. In its raised position gives the valve needle 13 contrast, the transition from the hardener supply line 9 in the chamber 11 free, so that the hardener H from the hardener supply line 9 in the chamber 11 can get. The activation of the actuator 12 of the hardener valve 10 takes place pneumatically via a compressed air control line 14 , which also from the left in the drawing end face of the valve assembly 2 goes out and in the actor 12 ends.

The chamber 11 in the valve assembly 2 is via a controllable shut-off valve 15 with the common output line 5 connected, with the shut-off valve 15 essentially from an actor 16 and one of the actor 16 driven and displaceably mounted valve needle 17 consists. In her right in the drawing stop position blocks the valve needle 17 the transition from the chamber 11 in the common output line 5 , so no hardener H out of the chamber 11 in the output line 5 can occur. The valve needle is in the left-hand position in the drawing 17 contrast, the transition from the chamber 11 to the output line 5 free, leaving the hardener H out of the chamber 11 in the output line 5 can reach there to mix with the base varnish SL to the multi-component water-based paint. The activation of the actuator 16 the shut-off valve 15 done by a compressed air control line 18 that of the left in the drawing end face of the valve assembly 2 goes out and to the actor 16 is guided.

For flushing the common output line 5 has the valve assembly 2 a detergent supply line 19 on, that of the left in the drawing end face of the valve assembly 2 goes out and a flushing valve 20 in the output line 5 opens, wherein the flushing valve 20 from a pneumatically actuated actuator 21 and one of the actor 21 driven and in the valve assembly 2 slidably mounted valve needle 22 consists. In its upper stop position in the drawing, the valve needle obstructs 22 the transition from the detergent supply line 19 to the common output line 5 so that no rinsing takes place. In a position lying in the drawing below, the valve needle 22 of the flushing valve 20 contrast, the transition from the detergent supply line 19 to the common output line 5 free, so the rotary atomizer 1 can be rinsed with a water-containing detergent V1, via the detergent supply line 19 is supplied. The activation of the actuator 21 of the flushing valve 20 pneumatically by a compressed air control line 23 that of the left in the drawing end face of the valve assembly 2 goes out and to the actor 21 is guided.

The Use of a water-based rinse is in use of a multicomponent water-based paint, since the master varnish used also based on water.

In addition, the valve assembly 2 another detergent supply line 24 on, that of the left in the drawing end face of the valve assembly 2 goes out and a flushing valve 25 in the chamber 11 opens, wherein the flushing valve 25 from a pneumatically actuated actuator 26 and one of the actor 26 mechanically driven and in the valve assembly 2 slidably mounted valve needle 27 consists. In a position lying on top in the drawing, the valve needle obstructs 27 of the flushing valve 25 In this case, the transition from the detergent supply line 24 in the chamber 11 , so that no detergent V2 is supplied. In a position lying down in the drawing, the Ventilna del 27 of the flushing valve 25 contrast, the transition from the detergent supply line 24 to the chamber 11 free, so that the detergent V2 from the detergent supply line 24 in the chamber 11 can penetrate. The activation of the actuator 26 takes place pneumatically via a compressed air control line 28 that of the left in the drawing end face of the valve assembly 2 goes out and to the actor 26 of the flushing valve 25 is guided.

In addition, the rotary atomizer points 1 nor a conventional main valve 29 on, that in the output line 5 is arranged and controls the delivery of the multi-component water-based paint, wherein the main valve 29 again from a pneumatically actuated actuator 30 and one of the actor 30 mechanically driven and in the rotary atomizer 1 slidably mounted valve needle 31 consists. The activation of the actuator 30 takes place pneumatically by another compressed air control line 32 that of the left in the drawing end face of the valve assembly 2 goes out and to the actor 30 of the main valve 29 is guided.

The following is now based on the schematic representation in 1a the operation of the valve assembly according to the invention 2 described.

In normal painting operation, the two rinsing valves 20 . 25 closed so that no rinsing takes place.

The hardener valve 10 and the shut-off valve 15 On the other hand, they are open during the normal painting operation, so that the hardener H via the hardener valve 10 , the chamber 11 and the open shut-off valve 15 in the output line 5 arrives where the hardener H mixes with the base paint SL, which on the open Stammlack valve 4 also in the output line 5 arrives. The resulting multi-component water-based paint is then from the rotary atomizer 1 according to the valve position of the main valve 29 applied.

During a brief interruption of the operation of the rotary atomizer 1 in contrast, the hardener valve 10 and the stem paint valve 4 closed, since no further hardener H and no further base varnish SL is needed.

In a longer interruption of operation of the rotary atomizer, for example, at the weekend, or at the end of the material-specific pot life, however, takes place a multi-stage flushing of the entire rotary atomizer 1 with the valve assembly 2 ,

As with a short-term interruption of the rotary atomizer 1 Here are the first hardener valve 10 and the stem paint valve 4 closed so that no further paint components H, SL are supplied.

Subsequently, the flushing valve 20 opened while the shut-off valve 15 and the other flushing valve 25 stay closed. About the detergent supply line 19 are then alternately pulse air PL and a water-containing detergent V1 supplied, which in the common output line 5 arrive and this and the entire rotary atomizer 1 from residues of the 2-component paint.

After this first flushing the flushing valve is 20 closed, whereupon the flushing valve 25 and the shut-off valve 15 be opened. About the detergent supply line 24 Then, an anhydrous, solvent-containing conventional detergent V2 is fed into the chamber 11 penetrates and over the open shut-off valve 15 in the output line 5 passes until the rotary atomizer 1 filled with the solvent-containing, anhydrous detergent V2 filled medium-containing, anhydrous detergent V2 filled and optionally rinsed. Then then the shut-off valve 15 and the flushing valve 25 closed, being in the chamber 11 Solvent-containing, anhydrous flushing agent V2 located prevents water-containing detergent residues of the detergent V1 in the rotary atomizer 1 or the valve assembly 2 react chemically with the hardener H, which in extreme cases to a clogging of the hardener valve 10 and could lead to the other valves.

That in the 2a and 2 B illustrated embodiment is largely consistent with that described above and in the 1a and 1b illustrated embodiment, so reference is made to avoid repetition of the above description and the same reference numerals are used below for corresponding components.

A special feature of this embodiment is that of the parent lacquer feed line 3 via a return valve 33 a return line 34 branches off, the return valve 33 again from a pneumatically actuated actuator 35 and one of the actor 35 driven and in the valve assembly 2 slidably mounted valve needle 36 consists. In a stop position located on the right in the drawing, the valve needle locks 36 the return valve 33 the transition from the parent lacquer feed line 3 in the return line 34 , so that no parent lacquer SL is returned. In a left in the drawing position is the valve needle 36 the return valve 33 contrast, the transition from the parent lacquer feed line 3 to the return line 34 free, so that a return of base varnish SL takes place. The return valve 33 For the base varnish SL is used for pressing and flushing the stock paint feed line 3 when using several different master paints SL with the same hardener H. The ver different master paints SL are then centrally connected to an upstream and not shown color changer and are as needed to the rotary atomizer 1 pressed. The activation of the actuator 35 the return valve 34 again takes place pneumatically by a compressed air control line 37 ,

The Invention is not limited to those described above embodiments limited. Rather, a variety of variants and modifications is conceivable who also make use of the concept of the invention and therefore in fall within the scope of protection.

1

rotary atomizers

2

valve assembly

3

Stock paint supply line

4

Stock paint valve

5

output line

6

actuator

7

valve needle

8th

Pneumatic control line

9

Hardener supply line

10

Hardener valve

11

chamber

12

actuator

13

valve needle

14

Pneumatic control line

15

shut-off valve

16

actuator

17

valve needle

18

Pneumatic control line

19

Detergent supply

20

detergent valve

21

actuator

22

valve needle

23

Pneumatic control line

24

Detergent supply

25

detergent valve

26

actuator

27

valve needle

28

Pneumatic control line

29

main valve

30

actuator

31

valve needle

32

Pneumatic control line

33

Recirculation valve

34

Return line

35

actuator

36

valve needle

37

Pneumatic control line

H

Harder

SL

stock paint

V1

hydrous Spülmit

tel

V2

anhydrous dish soap

PL

pulse air

Claims (19)

Valve arrangement ( 2 ) for the production of a multicomponent varnish, in particular a two-component water-based varnish, with - a stock paint feed line ( 3 ) for supplying a base varnish (SL), - a hardener feed line ( 9 ) for supplying a hardener (H), - an output line ( 5 ) for dispensing the multicomponent varnish mixed from the base varnish (SL) and the hardener (H), the stock varnish feed line ( 3 ) and the hardener supply line ( 9 ) in the output line ( 5 ), characterized by - a controllable shut-off valve ( 15 ) downstream of one in the hardener feed line ( 9 ) arranged hardener valve ( 10 ) is arranged. Valve arrangement ( 2 ) according to claim 1, characterized in that a first flushing agent supply line ( 19 ) in a line section downstream behind the shut-off valve ( 15 ) opens. Valve arrangement ( 2 ) according to claim 2, characterized in that the first flushing agent supply line ( 19 ) contains a water-containing detergent (V1). Valve arrangement ( 2 ) according to one of the preceding claims, characterized in that a second detergent feed line ( 24 ) in a line section between the hardener valve ( 10 ) and the shut-off valve ( 15 ) opens. Valve arrangement ( 2 ) according to claim 4, characterized in that the second detergent supply line ( 24 ) contains an anhydrous rinse (V2). Valve arrangement ( 2 ) according to one of the preceding claims, characterized in that between the hardener valve ( 14 ) and the shut-off valve ( 15 ) a chamber ( 11 ) is arranged for flooding with the anhydrous detergent (V2). Valve arrangement according to one of claims 2 to 6, characterized in that in the first detergent supply line ( 19 ) a controllable first flushing valve ( 20 ) and / or in the second detergent feed line ( 24 ) a controllable second flushing valve ( 25 ) is arranged. Valve arrangement ( 2 ) after one of vorge existing claims, characterized in that of the parent lacquer feed line ( 3 ) upstream of the stem paint valve ( 4 ) a return line ( 34 ) branches off, wherein in the return line ( 34 ) a controllable return valve ( 33 ) is arranged. Valve arrangement ( 2 ) according to one of the preceding claims, characterized in that the base paint feed line ( 3 ) downstream of the shut-off valve ( 15 ) in the output line ( 5 ) opens. Rotary atomizer ( 1 ) with an integrated valve arrangement ( 2 ) according to any one of the preceding claims. Painting machine, in particular painting robot, with a rotary atomizer according to claim 10. Operating method for a valve arrangement ( 2 ) for forming a multicomponent varnish, in particular a two-component water-based varnish, comprising the following steps: - feeding a parent varnish (SL) via a stock paint feed line ( 3 ), - supply of a hardener (H) via a hardener supply line ( 9 ), - mixture of the base varnish (SL) with the hardener (H) to the multicomponent varnish, - forwarding of the multicomponent varnish via an output line ( 5 ), characterized in that the hardener feed line ( 9 ) downstream behind one in the hardener feed line ( 9 ) arranged hardener valve ( 10 ) by a controllable shut-off valve ( 15 ) to prevent malfunction or damage to the hardener valve ( 10 ) to prevent. Operating method according to claim 12, characterized in that the shut-off valve ( 15 ) is closed when a coating operation is interrupted. Operating method according to claim 12 or 13, characterized in that the shut-off valve ( 15 ) is closed when flushing occurs. Operating method according to claim 14, characterized in that a line section between the hardener valve ( 9 ) and the shut-off valve ( 10 ) separated from a line section downstream behind the shut-off valve ( 15 ) is rinsed. Operating method according to claim 15, characterized in that the line section upstream of the shut-off valve ( 15 ) is flushed with an anhydrous rinsing agent (V2), whereas the line section downstream behind the shut-off valve (V2) 15 ) is rinsed with a water-containing dishwashing liquid (V1). Operating method according to one of claims 14 to 16, characterized in that downstream of the hardener valve ( 14 ) and upstream of the shut-off valve ( 15 ) a chamber ( 11 ), the chamber ( 11 ) is filled with the anhydrous detergent (V1) when the painting operation is interrupted. Operating method according to one of claims 11 to 17, characterized by the following steps for purging the valve arrangement: purging of the line section downstream behind the stop valve ( 15 ) with the water-containing dishwashing liquid (V1) with the shut-off valve closed ( 15 ), - then rinsing the line section upstream of the shut-off valve ( 15 ) with the anhydrous detergent (V2) with the shut-off valve open ( 15 ). Operating method according to claim 18, characterized by the following step: - filling of the line section between the hardener valve ( 10 ) and the shut-off valve ( 15 ) with the anhydrous rinsing agent (V2), - closing the shut-off valve ( 15 ) during an operation interruption, after the line section between the hardener valve ( 10 ) and the shut-off valve ( 15 ) was flooded with the anhydrous rinse (V2).