AVK 29/288 Series Manual

AVK UNDERGROUND FIRE HYDRANT
AVK UK Limited OM180907
OPERATION & MAINTENANCE MANUAL
29/288
The designs, materials and specifications shown are subject to change without notice due to our continuing programme of
product development.

1
OPERATION:
This series of screw-down Squat fire hydrants are suitable for use with clean water and neutral liquids, to a maximum
temperature of 70°C. Minimum liquid temperature must be above freezing. Insulation is essential for external
temperatures of 0°C and below to a limit of -10°C. They are rated for a maximum working pressure of 16 Bar unless
otherwise agreed and deliver a minimum of 2000 litres per minute at 1.7 Bar gauge.
They are normally supplied as CLOCKWISE TO CLOSE (CTC) denoted by a Direction ARROW on the Bonnet (12) and
a WHITE plastic insert (1) on the Stem Cap (3).
A BLACK plastic insert (1) denotes a Loose Stopper type which is only available on Squat Type.
A CLOCKWISE TO OPEN (CTO) version is denoted by the relevant Direction ARROW on the Bonnet (12) and a RED
plastic insert (1) on the Stem Cap (3).
OPENING / CLOSING Normally by standard Tee Key or Ring Key and Bar located on Stem Cap (3)
Closing Torque is in the region of 65Nm.
Number of Turns from fully closed to fully open: - Squat Type 7 approximately.
SWABBING It is not possible to use the Squat type for this purpose.
Only the Swept type is suitable for the introduction and retrieval of swabs.
It is recommended that applications in a corrosive atmosphere or sited in exposed locations or in the proximity of sea
water or spray, use a stainless steel stem 1.4404 (316) and all exposed fasteners are in A4 stainless steel. The
gunmetal outlet and class A coating (300 microns inside & out) are also recommended.
MAINTENANCE:
BS 750 only requires the provision for replacing Stem Seals under pressure & when the hydrant is in situ.
Refer to attached General Arrangement drawings
1.Replacement of stem seals and nylon bush (29.288.XXXXX)
2.Replacement of stopper (obturator) & bonnet 'O' ring seal (29.288.XXXXX. & 29.288.XXXXXB)
3.Replacement of outlet & outlet 'O' ring seal (29.288.XXXXX)
4.Replacement of drain plug or autofrost valve (29.288.XXXXXC)
SAFETY PRECAUTIONS
When changing obturator (stopper) and / or bonnet 'O' ring seal Maintenance Procedures must NOT be carried out
whilst the hydrant is installed in a live water main under pressure.
Check to ensure that there is no pressure in the main by opening the hydrant prior to commencing work.
Ensure the main will NOT be recharged before all work on the hydrant is completed.
All of the following procedures must be carried out with due regard to relevant
Road Traffic Act Guidelines, Health and Safety and COSHH directives.

1. PROCEDURE for Replacement of STEM SEALS & POLYAMID NYLON BUSH
TOOLS REQUIRED:
!5mm and 6mmA/F HexagonAllen Key.
!Slot headed screwdriver or thin blade
!Adjustable spanner, flat spanner or socket 17mm A/F
1) Remove plastic insert (1) by prising out using a thin blade.
2) Remove stem cap fixing bolt (2).
3) Remove stem cap (3).
4) Remove 3 No. M.10 Hex Head Screws and Washers (10&11)
5) Twist and pull the gland flange (6) upwards to remove from the stem (4). Remove the 'O' rings (7) and Bush (8)
and 'O' Ring (9)
6) Replace new 'O' rings (7) & (9) and Bush (8) by reversing operation described in clause (5). If necessary, lubricate
all 'O' rings with an approved grease.
7) Refit 3 No. M10 Hex Head Screws and Washers (10&11) and tighten.
8) Replace stem cap (3), Bolt (2) and Plastic Insert (1).
9) Open and close hydrant to check free running of stem.
2. PROCEDURE for Replacement of STOPPER (OBTURATOR) & BONNET 'O' RING
SEAL
TOOLS REQUIRED:
!5mm and 6mm A/F hexagon Allen Key.
!19mm A/F (for M.12) or 24mm A/F (for M.16) Spanners or Sockets
!Tee Key (or large adjustable spanner).
1) Ensure hydrant is in the partly open position by turning stem cap (3) in direction indicated for opening, one or two
turns to lift stopper off seat.
2) Remove 3 No. M.12 or M.16 Hex Head Screws (15) and Washers (16).
3) The bonnet can now be removed vertically with the stem (4) and stopper (20), it can be easily lifted out of the body. If
the hydrant is fitted with a loose stopper (20), this will remain on the valve seat when bonnet is lifted out of the body (21).
Remove 'O' ring (13).
4) Replace 'O' ring (13) locating in body (21) and if necessary lubricate with an approved grease.
5) Before locating bonnet/stopper (20) into body (21), check the stopper (obturator) (20) is well up the stem (4) by 3 or 4
full turns and ensure the stopper (obturator) guides are located to prevent the obturator turning on the stem. The
stopper (obturator) guides must both be on the same side of the body guide rails.
See diagram 29.288.XXXXXB
Safety Precaution : This procedure must NOT be carried out with the hydrant under pressure.
SAFETY PRECAUTIONS:
This procedure must NOT be carried out with the hydrant under pressure.
2

6) Fit bonnet (12) into Body (21) ensuring the 'O' ring (13) remains in position. When correctly aligned the plain face
on the bonnet (12) should be in line with the outlet.
7) Refit screws (15) and washers (16) and tighten.
8) Remove dust cap (17) from outlet (18)
9) Test hydrant as described on page 6.
10) Refit dust cap (17) to outlet (18)
3. Procedure for Replacement of FLANGED OUTLET and OUTLET 'O' RING SEAL
TOOLS REQUIRED:
24mm A/F Spanners or Sockets.
PROCEDURE FOR REMOVAL & RE-ASSEMBLY:
1) Remove dust cap (17) from outlet (18).
2) Remove outlet (18) by removing 4 No. bolts (15) and washers (16).
3) To replace the outlet (18) and 'O' ring (19), lubricate 'O' ring (19) if necessary using an approved grease then
locate it in the groove in body (21). Ensure dust cap (17) retaining ring is located in small groove on body (21) so
that a bolt (15) passes through the ring. Place outlet (18) in position, ensuring that 'O' ring (19) is still correctly
located and secure using 4 No. Bolts (15) and washers (16).
4) Test hydrant as described on page 4.
5) Refit dust cap (17) to outlet (18).
SAFETY PRECAUTIONS:
Ensure hydrant is closed prior to commencing procedure.
3

4. Procedure for replacement of AUTOFROST VALVE
TOOLS REQUIRED:
Short (stubby) screwdriver
Special fitting tool (C7322/161)
Tee Key (or large adjustable spanner)
PROCEDURE FOR REMOVAL AND RE-ASSEMBLY
1. Remove the dust cap (17) from outlet (18).
2. Insert the fitting tool to the autofrost valve (22) with a twisting motion. Squeeze the lugs of the autofrost valve (22)
together and push upwards, if necessary using a short (stubby) screwdriver, at the same time as pulling the special
tool and autofrost valve up through the hydrant body (21) and outlet (18). As shown on diagram 29.288.XXXXXC.
3. Smear a film of an approved grease on the “O” ring of the new autofrost valve (22)
Fit the new autofrost valve (22) to the fitting tool with a twisting motion and guide it into position through the outlet
(18) and into the body (21). Push down sharply so that the locking lugs protrude through the underside of the body
(21). Check by using the fingers, that the lugs are correctly located as shown on diagram 29.288.XXXXXC, then
slightly twist the fitting tool to dis-engage it from the autofrost valve (22) and withdraw it through the outlet (18).
4. Carefully open the hydrant to check satisfactory sealing under pressure.
The autofrost valve (22) will seal between 0.5 and 1 Bar pressure.
Then close hydrant and check that autofrost valve is draining correctly.
5. Refit outlet dust cap (17) to outlet (18).
TEST
On completion of Maintenance requirements:
1) Check all items are located correctly.
2) Check that all screws are secure.
3) Remove dust cap (17) from outlet (18).
SAFETY NOTE:
When pressurising the main, it is highly recommended that the hydrant is fractionally open to allow venting of air.
4) Check integrity of stopper (obturator) by closing the hydrant in the direction of the arrow on the bonnet.
5) Check integrity of the seals by SLOWLY opening the hydrant.
6) When all tests have proved satisfactory, close the hydrant.
7) Ensure dust cap (17) is always refitted to the outlet (18) when hydrant is not in use. This will prevent the ingress of
foreign matter, stones etc.
SAFETY PRECAUTIONS:
Ensure hydrant is closed prior to commencing procedure.
Ensure personnel are not directly above outlet during this part of the procedure.
4

A
5
Northampton Office
8 Rushmills, Northampton,
NN4 7YB England, UK.
Tel.: [phone]
Fax.: [phone]
Chesterfield Office
Colliery Close, Ireland Ind. Est., Staveley,
Chesterfield, S43 3FH, England, UK.
Tel.: [phone]
Fax.: [phone]
AVK UK Limited AVK UK Limited
ITEM DESCRIPTION QTY
1 2
3 4 5 6
7
8
9
10 11
12
13 14 15
16
17 18
19
20
21
22 23
INSERT,PLASTIC 1 CAPSCREW 1
STEM CAP 1
STEM 1
'O'RING 1
GLAND FLANGE
'O'RING
1
2
NYLON BUSH 1
'O'RING 3
HEX HEAD SCREW 3
WASHER 3 BONNET 1 'O'RING 1
THRUST COLLAR 1 pair
HEX HEAD SCREW 7
WASHER 7
DUST CAP 1
OUTLET 1
'O'RING 1
FIXED STOPPER 1
BODY SQUAT 1
LABEL IDENT / PAST TEST
1
AUTOFROST VALVE
1
ISSUE No.
DRAWN CHECKED
AA
DATE SCALE
AQUA-GAS No.
CUSTOMER No.
This drawing and the copyright therein are the property of AQUA-GAS MANUFACTURING LTD.,
and all information which it contains is confidential.
The drawing must not be reproduced or disclosed, nor must any information taken therefrom
be disclosed, without the prior consent in writing of AQUA-GAS MANUFACTURING LTD..
TITLE
MODIFICATION A4
AQUA-GAS MANUFACTURING LTD., DENBY WAY, HELLABY IND. EST., ROTHERHAM, S.YORKS.TEL:[phone] FAX:[phone]
GENERAL ARRANGEMENT - OPERATING AND MAINTENANCE INSTRUCTIONS FOR SERIES 29 SQUAT HYDRANT
29-288-XXXXX D.G.
10-10-2002
N T S
D.C.
AB
ISSUE 'AB'SEE MOD SHEET No 150 HEIGHT INCREASED FROM 247 TO 267 21-7-2003 D.G.
ISSUE 'AC'SEE MOD SHEET No 177 HEIGHT CORRECTED FROM 267 TO 274 26-1-2004 D.G.
AC
ISSUE 'AD' AUTOFROST VALVE MODIFIED 'O' SEAL TO TOUCH BASE OF CASTING 5-7-2004 D.G.
AD
125
286
274
1
2
3
4
8
9
10
11
6
5
14 15
16
12
13
20 21
17
18
19
22
7
23
15 16

A
6
Northampton Office
8 Rushmills, Northampton,
NN4 7YB England, UK.
Tel.: [phone]
Fax.: [phone]
Chesterfield Office
Colliery Close, Ireland Ind. Est., Staveley,
Chesterfield, S43 3FH, England, UK.
Tel.: [phone]
Fax.: [phone]
AVK UK Limited AVK UK Limited
This drawing and the copyright therein are the property of AQUA-GAS MANUFACTURING LTD.,
and all information which it contains is confidential.
The drawing must not be reproduced or disclosed, nor must any information taken therefrom
be disclosed, without the prior consent in writing of AQUA-GAS MANUFACTURING LTD..
MODIFICATION A3
MACHINING DATA
MAT./PATT. No.
PROJECTION
TO B.S.308
TITLE - LOCATION OF STOPPER
MATERIAL
SCALE NTS
DRAWN D.G.
CHECKED D.C
DATE 10-10-2002
ISSUE
No.
DRAWING No.
AQUA-GAS MANUFACTURING LTD., DENBY WAY, HELLABY IND. EST., ROTHERHAM, S.YORKS.TEL:[phone] FAX:[phone]
29-288-XXXXX B
A
NOTE : OBTURATOR (STOPPER) GUIDES MUST BOTH BE LOCATED
ON THE SAME SIDE OF THE BODY GUIDE RAILS
BODY GUIDES
OBTURATOR
(STOPPER)
GUIDES

A
7
Northampton Office
8 Rushmills, Northampton,
NN4 7YB England, UK.
Tel.: [phone]
Fax.: [phone]
Chesterfield Office
Colliery Close, Ireland Ind. Est., Staveley,
Chesterfield, S43 3FH, England, UK.
Tel.: [phone]
Fax.: [phone]
AVK UK Limited AVK UK Limited
STEP 4
ISSUE No.
DRAWN CHECKED
A
DATE SCALE
AQUA-GAS No. CUSTOMER No.
This drawing and the copyright therein are the property of AQUA-GAS MANUFACTURING LTD.,
and all information which it contains is confidential.
The drawing must not be reproduced or disclosed, nor must any information taken therefrom
be disclosed, without the prior consent in writing of AQUA-GAS MANUFACTURING LTD..
TITLE
MODIFICATION A4
AQUA-GAS MANUFACTURING LTD., DENBY WAY, HELLABY IND. EST., ROTHERHAM, S.YORKS.TEL:[phone] FAX:[phone]
STEP 1 TOOL
REPLACEMENT OF AUTOFROST VALVE
29-288-XXXXX C D.G.
26-3-2003
N T S
D.C.
STEP 3
STEP 2
ENSURE LUGS HAVE PROTRUDED THROUGH CASTING
STEP 2
STEP 1 TOOL
AUTOFROST VALVE
STEP 3
CORRECT
INCORRECT
AB
ISSUE 'AB'SEE MOD SHEET No 151 SHAPE OF TOOL ALTERED 21-7-2003 D.G.
AC
REMOVAL
(C7322/161)
FITTING
ISSUE 'AC'SEE MOD SHEET No 180 REMOVAL & FITTING STAGES 1,2,3 & 4 ADDED ALSO BALLOONS WITH ITEMS ADDED 18-2-2004 D.G.
AD
ISSUE 'AD' AUTOFROST VALVE MODIFIED AS MOD 133 DRGALT TO SUIT 5-7-2004 D.G.
22
18
21
18
22
21