PVC CASING PIPES 

HASSPIPE produces a high quality range of PVC-U well casings and screens strictly in accordance with the Standard TS 11794 and ISO standarts, class I, II and III. The standard TS 11794 and ISO applies as well for raw materials and workmanship of pipes used in the manufacture of the casing and screen. There are three basic ranges - a standard range for shallow, medium well depth and a heavy duty, thick walled range for greater well depths.

The casing and screens are made from 100% virgin unplasticized poly vinyl chloride compound and are coloured grey. They are supplied with a male pipe thread at the spigot end and a female pipe thread at the socket end. No re-worked material is used.

The pipe is produced under ISO 9001:9002 Quality Management System.

Screens can be supplied with either a plain or filtered surface. Slots are arranged vertically to improve the mechanical strenght of the screens and are designed to give open areas ranging from 6% to 12% depending on the size and slot width. 

Materials: PVC-U 

Lengths: Normally supplied in 2m. - 3 m. and 4 m. lengths. Other lengths available on request. 

Slot Sizes: Available slot width 2.0 mm. 

Thread Style: Mechanical jointing by threaded connection to TS 11794 with trapezoidal thereads. 

Joints: Each length is supplied with a Male/Female socketed joint as standard. 

Marking: Standard marking is applied to all casing and screen.

Dimensions of well casing and screens for 100 meter depth

The covers of pipes up to 100 meters depth are BLUE

Dimensions of well casing and screens for 300 meter depth

The covers of pipes up to 300 meters depth are RED

Trapeze Thread System Dimensions

OTHER FEATURES OF HASS RIGID PVC DEEP WELL PIPES

Although the pipe weights cause an axial stress during lowering into the well, both the pipe and the thread structure are loaded to meet these loads.

Sheet and plastic well pipes should be chosen depending on the soil structure. The well pipes produced by Hass apre resistant to chemical effects such as acid and base since they are made of hard PVC. This provides continuity and economy in the business.

Hass plastic deep well pipes are divided into three classes according to their usage depth or pressure strength in normal grounds.

Class 1 pipes, 300 m - 500 m depths of deep wells,

Class 2 pipes, 100 m - 300 m depths of deep wells,

Class 3 pipes are used in 0 m - 100 m depths of deep wells.

Connection Type and Thread Feature of Hass Rigid PVC Well Pipes

HASS RIGID PVC FILTERED (STRAINER) AND CLOSED DEEP WELL PIPES;

One of the ends is male-headed with external pass, the other ends are female-headed internal pass.

As can be seen in the picture, the teeth of the passes are trapezoidal thread and the female pass is countersunked to allow easy insertion of the male headed pass to the female head to ensure easy assembly to each other.

This ensures a safe and easy connection of the pipe, and no fittings are required.

CONSIDERATIONS IN THE STORAGE AND USE OF PLASTIC PVC DEEP WELL PIPES

 1. Care should be taken to protect the threaded parts from impacts during transportation.

2. It should be protected against deformation and sunlight during storage and should be stacked on wooden wedges.

3. Thread protectors on trapezoidal thread pipes should not be removed until the pipes are used.

4. For easy entry of pipe threads, grease and so on. Do not use oils, water and soap are sufficient.

5. Do not apply glue to keep the threads of the pipe well. The adhesive spoils the teeth and melts the pipe.

6. Pump selection should be made by considering the inner diameter of the pipes.

Critical Crumbling Pressures of Deep Well Pipes; 

The geological units and structures show different characters as you go deeper into the soil, and the problems that can be encountered in the wells are different. Under normal conditions, vertical stresses increase with depth and are greater than horizontal stresses. But; Events such as tectonic stresses, geological structural changes, the structure of faults and folds, temperature of the environment, discontinuity of the layers increase the horizontal stresses and in some cases the horizontal stresses can be greater than the vertical stresses. When choosing a well pipe, especially horizontal stresses should be known and pipe selection should be made accordingly. While vertical stresses (Sv) increase linearly with depth in normal soils, horizontal stresses (Sh) also increase accordingly.

Sh / Sv = k; It is expressed as K = V / (1-V).

Here, V = Poison ratio is 0.25 in rocks with elastic behavior and 0.50 in rocks with plastic behavior.

For normal reasons; Sv = g.h and Sh = k.Sv = (V / (1-V)). G.h.

Here; h = height, g = density of the rock.

As a result of the studies carried out in different regions and rocks; A correlation of 0.3 + 100 / h <k <0.5 + 1500 / h was obtained.

It is given by the equation Pk = (2E / 1-V2) .1 / (SBO-1) 2). Here; Pk = Critical slump pressure, E = modulus of elasticity, V = Poison ratio, SBO = Standard size ratio (D / t). The critical slump pressure in horizontal slotted filtered pipes is approximately 0.5 - 0.7 times that of closed pipes.

When deep well pipes are lowered into the well under vertical forces due to their own weight; It is also subjected to lateral forces during graveling, drilling mud cleaning and well development (pumping). It is essential that pipes withstand these lateral forces and can withstand these forces up to critical collapse pressures. For this reason, lateral forces that will occur in the wells should be found and should be taken into consideration in pipe selection.

Well Screens

The well screens slits of the pipes are opened 2 mm wide, perpendicular to the pipe axis, in accordance with TS 11794 standards.

Fittings