Havestock has been audited by Standards Australia with respect to
the StandardsMark program. Technical information provided in this section includes :
Installation instructions and rebate drawing are dealt with in the following section of this catalogue (Section 19).
Havestock has been audited by Standards Australia with respect to
the StandardsMark program.
At the time of printing, Havestock is the first and only manufacturer and supplier of access covers to be awarded the StandardsMark to AS3996 and Quality Assurance to AS/NZS ISO9002.
StandardsMark Licence is enclosed in this section for your information.
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18.2 Australian Standard -
AS3996
Havestock products are specifically designed and tested to ensure compliance with the Australian Standard AS3996. The basis for the most common usage classes provided by the Standard are indicated below - refer to the Standard for a detailed specification.
Note :
|
Classification |
Design Test Load Only |
AS3996 Classified Usage Descriptions | |
|
Class A |
|
10 kN |
|
|
Class B |
|
80 kN |
|
|
Class C |
|
150kN |
|
|
Class D |
|
210 kN |
|
|
Class E |
|
400 kN |
|
|
Class F |
|
600 kN |
|
|
Class G |
|
900 kN |
|
Havestock products are tested to AS3996 standards, as per our Quality Assurance Procedures Manual.
Load testing is carried out on Havestock’s purpose built Load Test Cell which is fully calibrated and approved by Standards Australia. Load tests are conducted regularly and reports are available on request ~ please contact the Havestock Quality Manager.
Third party testing is also carried out at the Physical Infrastructure Centre at the Queensland University of Technology’s (QUT) Faculty of Built Environment and Engineering.
The following pages include some results of internal and third party tests of products. Further information may be obtained by contacting the Havestock Quality Assurance Manager.
Please note that tests carried out prior to 1992 where conducted under the accepted British Standard B.S. 497 Part 1-1976.
Havestock testing is now carried out in accordance with the new Australian Standard AS3996-1992 (Access Covers & Road Grates). Where required, testing can also be carried out to British Standards BS497 or European Standards EN124.
Testing under AS3996 (using 240x240mm test block) includes both Type and Proof Loadings.
| Class | Usage | Type
Test |
Proof
Cast Iron |
Proof
Ductile Iron |
| Class A |  |
10kN | 10kN | 7kN |
| Class B |  |
80kN | 80kN | 57kN |
| Class C |  |
150kN | 150kN | 100kN |
| Class D |  |
210kN | 210kN | 140kN |
The material used for casting of product depends on the load classification required. Havestock uses both grey cast iron and ductile iron. Material testing is confirmed through third party testing as detailed in the Havestock Quality and Procedures Manual.
These materials conform with the following Australian Standards :
18.5 Comparison Between Standards
Subject: Design Load Testing Requirements
Design Load, for access covers, sump grates and road gully grates, is covered by the Australian Standard AS3996-1992. However due to the "newness" of the Standard, some suppliers and specifiers still refer to the previously used British Standard. This British Standard (B5497) has now been replaced by all EEC countries by the new European Standard EN124.
Overview of Standards
Whilst various Standards have been used for this very vital aspect of these products, one wonders about the acceptance of other than the Australian Standards in the case of litigation. Given this attitude, Havestock have taken the stand that we will only work to the Australian Standard AS3996 and all test certificates issued will be relevant to the Australian Standard.
Comparison of Standards
Although Havestock only comply to the Australian Standard, the following information is supplied to allow comparisons of the other Standards.
Australian Standard (AS3996) Type Test
Under the Australian Standard a Type Test should be conducted on each product or product variation. This Type Test does not take into consideration the material from which the product is made but just that the product from each Class will meet the specific "Minimum Ultimate Limit State Design Load (kN)". Therefore under the Australian Standard it is not sufficient to provide only test reports for Proof Testing.
We have seen cases where mild steel gully grates have been tested using only the Proof Test Load and met the requirement but would be totally destroyed when applying the Type Test Load. Type Testing under the Standard requires the product meet the "Minimum Ultimate Safe Design Load (kN)" without failure or in the case of some materials; a maximum permanent deflection Type Testing.
For the normal range of recessed covers of Classes (eg. Class A, B, C & D) Type Testing will be carried out without concrete infilling and for Classes E, F & G with concrete infilling in place. This concrete will be of a minimum compressive strength of 32mpa (AS1379).
Type Testing under AS3996 is always carried out using a bearing block 240x240mm.
European Standard (EN124) Type Test
Type Testing under this Standard is somewhat different to our Australian Standard in that all recessed covers are tested after filling with concrete to suppliers stated requirements.
Testing is carried out using a 250mm diameter bearing block for the normal range of products (clear openings 300 - 1000m). Two thirds of the nominated test load is applied to the product and the permanent set calculated and this must be less than 1/500 of the clear opening. The full test load is then applied and this must be achieved as nominated : "specimens shall not show cracks in the course of the test."
British Standard (BS497 Part 1)
Under this Standard all tests are carried out using a 300mm diameter bearing block and in the case of recessed covers, before filling with concrete (Grade A, B & C). With other grades, again testing should be performed after filling with concrete.
Comparison of Standards - Design Load
Whilst these standards are somewhat different in their concept, it can be argued that they have all originated from the 1987 version of the British Standard and that all current Standards are now very similar in application.
|
Generic Description |
AS3996 240x240mm Block |
EN124 250mm Dia. Block |
BS497 300mm Dia. Block |
| Light Duty |
Class A l0kN |
l5kN |
l0kN |
| Intermediate Duty |
Class B 80kN |
125kN |
N/A |
| Medium Duty |
Class C l50kN |
N/A |
l50kN |
| Heavy Duty |
Class D 2l0kN |
250kN |
250kN |
| Extra Heavy Duty |
Class E 400kN |
400kN |
500kN |
| Special Heavy Duty |
Class F 600kN |
600kN |
N/A |
| Airports |
Class G 900kN |
900kN |
N/A |
Based on this comparison, the following condusions are deduced:
Summary & Conclusions
The three systems:
All are very similar in the requirements of Design Load. The Australian Standard however is obviously the Standard that should be nominated for projects within Australia or for projects funded by Australia.
From the above information, it can be readily seen that for light duty product, all three Standards are identical.
At the other end of the normal range, again all three systems are very similar with BS497; accepting a slightly lessor load and when designers talk about 36 tonnes and 50 tonnes (design load) they are infact alluding to the 1967 version of the British Standard and we should endeavour to bring these people up to current Standards requirements.
18.6 New AS3996 v’s old British Standard
The new Australian Standard has now been published and it's introduction has made quite a significant change to the duty rating of access covers and gratings which are used in sewerage, stormwater and drainage applications.
Many hydraulics engineers, Government departments, plumbers and builders are unaware of the new Standard and are still calling for the old style of product.
The new Standard ensures a closer fit between the actual load ratings required and the product's capabilities.
Before this standard was introduced, the industry used the British system of Light, Medium and Heavy Duties and it is necessary to have a comparison between the old system and the new Australian Standard.
| New
"Class"
System |
Usage | Old System | AS3996
Aust. |
BS497
UK |
| Class A | |
Light | 10kN | 10kN |
| Class B | |
80kN | ||
| Class C | |
Medium | 150kN | 150kN |
| Class D | |
Heavy | 210kN | 250kN |
Some suppliers of product are not following this type of analysis and are in fact stating that "Class B" products are equal to the old Medium Duty unit.
Clearly this is not the case and for your own benefit, just look at a Havestock Class C (Medium Duty) cover; you will note that it is 95mm deep. A "Class B" cover is only 55mm deep.
Customers and specifiers should also be insisting on a Certificate of Conformance that access covers or gratings are covered by an accredited Quality Assurance Programme to AS3902.
This ensures that product supplied conforms with designed drawings and has been statistically tested by a third party testing facility to meet the required Proof & Type Test loads applicable to the new class ratings.
Please nominate all your new requirements relative to the new Standards to overcome site problems and ensure future replacement of products.
All products are inspected against a Quality Assurance Checklist prior to delivery.
Sizing to drawings, Keyhole gauge fit, Gas tightness, Anti-rocking, Machining, General Appearance, Packaging
As required, Havestock will issue a Certificate of Conformance specific to the customer, product and site.
Havestock grates are designed to suit the requirements of AS3996 which includes Bicycle Safety.
The Standard AS3996 (Appendix D) states :
As you can see the tougher test is conducted with the smaller 610mm diametre wheel.
610mm diametre will have a 5mm penetration if the gap between the bars is 110mm. In third party tests comissioned by HavestockIt has been confirmed that a wheel of
Consequently any bar spacing of less than 110mm will be bicycle safe under the Standard.
Physical tests are also conducted at QUT as required.
Date : 15/02/95
The hydraulic capacity of grates and frames is of importance in determining the product to be used for a specific project.
The Havestock range of sump, trench and road grates have been designed for strength rather than hydraulic capacity in mind, and are therefore limited to some 76.5 litres per second of square metres of pit clear opening. This is however offset by the ability of the products to meet the design load and bicycle safety under the new Australian Standard AS3996-1992.
In terms of hydraulic capacity, the Havestock "Hinged Road Grate & Frame" has been tested to have a flow rate of 72.0 litres per second under static head conditions. However, in use as a side entry gully grate, other factors must be taken into account.
Factors :
Grate opening as a percentage of clear opening.
Volume of water and ponding effect.
Volume of water which actually enters via the gully gap.
Angle of gully box to roadway.
Pit water level.
Clogging.
Kerb extension.
Roadway capacity.
Hyrdoflow effect of transverse bars as a result of low pressure along the fluted edge.
Area of sag.
Therefore the selection of a gully grate is somewhat difficult in terms of the "Total Hydraulic Effect".
The following flow chart has been prepared using the accepted John Hopkins University Formulae (Design of Stormwater Inlets - John Hopkins University, Baltimore 1956) and then adapted to consider the above factors. Obviously under test conditions, "Total Hydraulic Capacity" as shown in the following graph can be substantiated.
In terms of clogging, the Havestock grate has been designed with wide spaces between main longitudinal bars and together with closer transverse bars at smooth height, ensures that debris is swept past the intake area of the grate; thereby ensuring relatively little loss of capacity from clogging. Clogging has also been factored into the determination of "Total Hydraulic Effect".
The term "Total Hydraulic Effect" (T.H.E.) has been developed by Havestock to truly represent the effectiveness of a gully grate in the normal situation. It takes account of the variable factors that exist in a kerb draw such as head, clogging and hydraulic effect. "T.H.E." should not be compared in a single environment to the hydraulic capacity of some other grate manufacturers due to the variety of unknown factors which take effect on the capture of the water flow. However, it is fair to say that the "T.H.E." of the Havestock unit will meet most requirements in a grade situation of 1.30, with little or no clogging.
As required by the Queensland Urban Drainage Manual (September 1992), all Local Authorities are required to have available pit inlet capacity charts for stormwater systems. Similarly the use of Australian Standard AS 3996-1992 "Access Covers and Road Grates and Frames" is in the interest of all local authorities and Havestock with it’s Class D hinged road grate & frame is able to meet the requirements of both of these publications.
The Havestock Drainway system having slightly more open area relative to grate size, potentially has a slightly higher "THE" than the standard road grates based on the normal 900x600 grate size. The Havestock Drainway grate increases the Total Hydraulic Effect by a factor of 1.14.
Flow Rates – Sump & Trench Grates
Total Hydraulic Effect (T.H.E.) of sump grates and frames tends to be fairly static as these units are normally installed in flat areas such as car parks or in flat situations at the bottom of small gradients.
Therefore, the following sump grates are detailed with their relative T.H.E.
Clear Opening T.H.E.
300x300 - 7 litres per second
450x450 - 16 litres per second
600x600 - 27 litres per second
900x600 - 42 litres per second
In terms of trench grates or sump grates in gradient situations, the T.H.E. must take into account the issues as follows :
where grate is installed at the gradient angle then some hydraulic capacity is lost due to the speed of the water on the gradient causing grate bypass.
where grate is installed flat at the bottom of gradient, the water capture is at maximum but some doubt is placed on the weight carrying capacity of the grate.
The following table and chart gives T.H.E. of standard grates under gradient conditions. These rates of flow do not consider any head conditions but take into account speed of water flow on gradient and momentum of water at angle in incidence to the grate.
| Sump Grate | Nil Gradient | 1:10 Gradient | 1:20 Gradient | 1:10 Gradient | 1:20 Gradient |
| Clear Opening | At gradient angle | At gradient angle | Normal to gradient | Normal to gradient | |
| 300x300 |
7 ltrs/sec |
6 |
6 |
10 |
9 |
| 450x450 |
16 |
19 |
17 |
25 |
20 |
| 600x600 |
27 |
35 |
30 |
50 |
46 |
| 900x600 |
42 |
51 |
48 |
71 |
66 |
| Trench Grate | Nil Gradient | 1:10 Gradient | 1:20 Gradient | 1:10 Gradient | 1:20 Gradient |
| Clear Opening | At gradient angle | At gradient angle | Normal to gradient | Normal to gradient | |
| 150 |
5 ltrs/sec |
4 |
5 |
8 |
8 |
| 225 |
16 |
21 |
18 |
35 |
31 |
| 300 |
37 |
41 |
40 |
62 |
57 |
| 450 |
51 |
53 |
55 |
79 |
77 |
As part of our Quality Assurance Program, all products (access covers and grates), have a number of markings either cast in or painted onto the product.
| Silver Paint Stripe | Product received but either not inspected or rejected |
| Yellow Paint Stripe | Passed Inspection |
| Red Paint Stripe | Passed tests for design load and metal composition |
| Green Paint Stripe | Passed all inspections and totally meets our requirements |
| Serial Number (Prefixed ‘C’) | Cast Iron inspection number |
| Serial Number (Prefixed ‘M’) | Mild Steel inspection number |
| Name of Manufacturer | Cast into the product or on an attached plate |
| Product Type | Class & Type (ie sealed) |
Delivered Weight
The total weight of the unfilled cover and frame, as delivered, and that weight to pick up the cover and frame unit.
Filled Weight
Total weight of the cover when filled with concrete (2235 kg/m3) infill and that weight to be lifted to pick up the cover.
Lifting Weight (Kg's)
Class A Sealed
|
Product Code |
Delivered Wt. |
Filled Wt. |
Lifting Wt. (traditional) |
| A33A | 25 | 33 | 15 |
| A44A | 36 | 41 | 21 |
| A46A | 41 | 48 | 24 |
| A66A | 49 | 52 | 28 |
| A76A | 59 | 69 | 35 |
| A77A | 70 | 81 | 40 |
| A96A | 70 | 81 | 40 |
| A97A | 100 | 115 | 58 |
| A99A | 110 | 130 | 66 |
Class B Sealed
|
Product Code |
Delivered Wt. |
Filled Wt. |
Lifting Wt. (traditional) |
| A33B | 25 | 33 | 15 |
| A44B | 36 | 41 | 21 |
| A46B | 41 | 48 | 24 |
| A66B | 49 | 52 | 28 |
| A76B | 59 | 69 | 35 |
| A77B | 70 | 81 | 40 |
| A96B | 70 | 81 | 40 |
| A97B | 100 | 115 | 58 |
| A99B | 110 | 130 | 66 |
Class C Sealed
|
Product Code |
Delivered Wt. |
Filled Wt. |
Lifting Wt. (traditional) |
| A33C | 41 | 36 | 18 |
| A44C | 71 | 68 | 34 |
| A46C | 84 | 90 | 45 |
| A66C | 95 | 110 | 55 |
| A76C | 118 | 125 | 63 |
| A77C | 127 | 140 | 70 |
| A96C | 136 | 155 | 78 |
Class D Sealed
|
Product Code |
Delivered Wt. |
Filled Wt. |
Lifting Wt. (traditional) |
| A44D | 71 | 68 | 34 |
| A46D | 84 | 90 | 45 |
| A66D | 95 | 110 | 55 |
| A76D | 118 | 125 | 63 |
| A77D | 127 | 140 | 70 |
| A96D | 136 | 155 | 78 |
| A99D | 183 | 198 | 99 |
The actual weight lifted in order to lift the cover out of the frame under normal opening conditions. (ie approximately half of the filled weight, For LiteLift Covers it is approximately half of the Delivered Weight.)
Note :
All keyholes allow the use of Standard lifting keys. Covers are manufactured with four (4) keyholes to allow for ease of lifting. Obviously when opening access covers, a piece of water pipe should be used to roll the cover out of the way.
The new range of LiteLift covers have been designed to have a low lifting weight. Contact the Havestock Technical Sales department for detailed information.
Conditions of Accepting Orders.
Cancellation of orders.
Returns.
Delivery.
Prices.
Payment Terms and Conditions.
Ownership
