STK-1 / STK-2

A Unique Package of Irrigation Products Designed To Cool and Clean Synthetic Turf Sports Fields

Simple to specify, contractor-friendly to install, and easy to service and maintain for the end-user, the Hunter ST System is the first and only cost-effective, fully integrated solution designed to exceed the unique and specific needs of the synthetic turf irrigation market.

The Hunter ST System features gear-driven long-range rotors based on Hunter's legendary rotor technology coupled with a special multi-axis swing joint, low-pressure loss valves and a robust feature-packed vault. Combined, they provide the ultimate in installation flexibility and long-term total access to all irrigation components, including the swing joint point of connection. Such complete access is an absolute must when the surrounding synthetic surface is not easily excavated and restored to original condition without huge expense and specialized equipment and procedures.

Product Tabs

Features

Standard installed nozzle: #73
Arc adjustment: Through-the-top
Arc setting: 40° to 360°
Quick check arc mechanism
Gear-drive: Water lubricated
Factory installed rubber logo cap
Nozzle trajectory: 22.5°
5-year component part warranty

ST Rotors: ST-90 / STG-900 [1]

Hunter synthetic turf rotors are designed specifically to satisfy the unique needs of synthetic turf irrigation. Robust, reliable, and engineered for longevity in high flow and high pressure conditions, ST rotors in the 103' to 120' category are available in two configurations:

ST-90

This model features a smaller exposed surface area and jar-top access to the riser assembly. The ST-90 is ideally suited for direct burial in the natural turf that is sometimes adjacent to the synthetic field to be irrigated.

STG-900

Featuring a slightly larger exposed surface area, this model includes through-the-top access to the riser assembly. The STG-900 is ideally suited for installation within the ST vault that is installed under the synthetic surface. It can also be installed in the natural turf that is sometimes adjacent to the synthetic field to be irrigated.

ST "VA" SWING JOINT: ST-2008VA [2]

Traditional swing joints will cause the rotor to move back and forth as the elevation of the rotor is raised and lowered. While appropriate for natural turf installations, synthetic turf systems require a completely different approach. The best way to support the rotor's tremendous lateral thrust during operation is to place the rotor in a snug fitting hole within the vault's cover set. In order to set the rotor perfectly to grade and in this very specific location the swing joint must provide flexible movement in every direction, not only up and down, but also forward, backward, left and right. Ideally, this flexibility would include the ability to "reset" the elevation grade of the rotor should the enclosure settle downward during the vibratory compaction of the surrounding field base material. Enter the Hunter Vertical Alignment (VA) swing joint. Offering the ultimate in flexibility, our vertical alignment swing joint includes six pivot points for multi-axis movement plus a seventh pivot at the outlet for rotational adjustments of the valve and rotor assembly. Constructed of rugged 2" PVC pipe and fittings, this 315 PSI rated swing joint dramatically reduces dangerous water velocities and performance robbing pressure loss through the ST System's components.

ST VAULT SYSTEM: ST-173026B [3]

The Hunter ST vault's complimentary blend of features include construction grade fiberglass in the body, high impact polymer-concrete on the exposed upper rim and a near indestructible polymer-concrete cover set. Together, they form a 20,000+ lb. rated enclosure that is durable, yet easy to install at 105 lbs. with the covers removed.

The exclusive 2” thick three-piece polymer-concrete cover set has a perfectly located cast-in hole for the STG-900 rotor on one side. This design allows the rotor to be held perfectly to grade within the hole while the enclosure is back-filled from the exposed opposite side. Quick couplers are a must-have around every synthetic field. The cast-in quick coupler port and cover on the opposite side eliminates the need for separate quick coupler enclosures around the playing field.

Quick Coupler

All ST Vaults include convenient quick access ports. Quick-couplers provide a convenient source of water for washing down spills and water-soluable paint. Integrated in-vault design eliminates the need for additional quick-coupler enclosures.

Clear Advantage of the Hunter ST Vault

Have you ever tried to bore a hole into polymer-concrete? It is near impossible. How about installing and setting a 400 lb. polymer-concrete enclosure? Not very much fun.

We designed the ST vault to be as lightweight and easy to install as possible without sacrificing durability. From the functionality perspective, the three-piece cover, large interior space and total top access to all components make servicing easier and the system less expensive to maintain.

ST VALVE CONFIGURATION: ST-VBVFK [4]

For some, the preferred approach to designing synthetic turf irrigation systems is the "block" type configuration with remotely located valves that are off the synthetic surface. The benefit of this configuration is that it removes all high-pressure mainlines from beneath the synthetic surface. Through the use of a remotely located isolation valve, constantly pressurized supply lines to the quick couplers can be removed from beneath the synthetic surface as well.

For others, the preferred approach is to use valve-in-head (VIH) rotors. However, typical VIH rotors have an unacceptably high-pressure loss at the high flows and pressures that are inherent in all synthetic turf irrigation systems. As a result, the Hunter ST System utilizes a valve adjacent to head (VAH) configuration. This design lowers the pressure loss down to a very acceptable 3.9 PSI at 75 GPM through the valve assembly.

Models

STK-1 / STK-2 Model Chart

The ST Kits	STK-1	STK-2
For specification ease and to ensure the correct product is installed, the ST System is available in kit configurations.	STG-900 Block System (remotely located valve)	STG-900 VAH System (valve adjacent to head)
ST Rotor	STG-900	STG-900
ST Vault	ST-173026B	ST-173026B
ST Swing Joint	ST-2008VA	ST-2008VA
ST Valve and Fitting Kit	—	ST-VBVFK
ST Adapter Fitting(s)	239300 and 239800	239800
Rubber Cover Kit	473900	473900
Quick Coupler	HQ5RC	HQ5RC

STK-1 / STK-2 Components	Description
STG-900	Synthetic Turf Rotor without rubber cover kit
ST-173026B	Vault with 3-piece polymer-concrete cover
ST-2008VA	"VA" 2" PVC Swing joint with 6 pivot points
ST-VBVFK	ICV-151 valve, high pressure rated ball valve and fitting kit
239800	Adapter Elbow Fitting: Connects ST-2008VA swing joint to rotor adapter fitting (STK-1). Also connects ST-VBVFK to STG-900 rotor (STK-2).
239300	Rotor Adapter Fitting: Connects 239800 adapter elbow fitting to STG-900 rotor's Acme inlet (STK-1)
473900	Rubber Cover Kit: STG-900 Rubber Cover Kit
HQ5RC	Quick Coupler Valve: 1" inlet with 1-1/4" outlet for key

ST SYSTEM DETAILS AND INSTRUCTIONS

Every ST Kit also includes a set of concise installation details and installation instructions. Each installation detail contains more than 20 callouts and references to ensure the system is installed to the exact and intended specifications.

STK-1	STK-2
"OFF FIELD SIDE" "ON FIELD SIDE"	"OFF FIELD SIDE" "ON FIELD SIDE"
"VIEW FROM ON FIELD SIDE"	"VIEW FROM ON FIELD SIDE"

STK-1

STK-2

"OFF FIELD SIDE"

"ON FIELD SIDE"

"OFF FIELD SIDE"

"ON FIELD SIDE"

"VIEW FROM ON FIELD SIDE"

"VIEW FROM ON FIELD SIDE"

	ST-90*	STG-900*
Overall Height	11-1/2"	14"
Pop-up Height	3"	3"
Exposed Diameter	5-1/2"	8"
Inlet Size	1-1/2" NPT	1-1/2" Acme
	*Not for use with the ST Vault	*For use with the ST173026B Vault

SPECIFICATION BUILDER

MODELS	STANDARD FEATURES	FEATURE OPTIONS	NOZZLE OPTION
ST-90 = 3" Pop-up	Jar top cap synthetic turf rotor, adjustable arc with plastic riser, NPT inlet threads	B = BSP inlet threads	#73 = Factory installed nozzle number
STG-900 = 3" Pop-up	Top service synthetic turf rotor, adjustable arc with plastic riser, ACME inlet threads		#73 = Factory installed nozzle number

EXAMPLES

ST-90 - 73	3" pop-up, jar top cap, adjustable arc, plastic riser, NPT inlet threads, and #73 nozzle
STG-900 - 73	3" pop-up, top service, adjustable arc, plastic riser, ACME inlet threads, and #73 nozzle

Specifications

Operating Specifications

Radius: 103' to 120'
Flow rate: 74.5 to 92.0 GPM
Operating pressure range: 100 to 120 PSI
Precipitation rate: 1.25 in/hr approx. (180 degrees)

User Installed Options
Rubber Cover Kit ST-90 (P/N 234200)
Rubber Cover Kit STG-900 (P/N 473900)

ST-90 / STG-900 Nozzle Performance Data

Nozzle	Pressure (PSI)	Radius (ft.)	Flow (GPM)	Precip in/hr
Nozzle	Pressure (PSI)	Radius (ft.)	Flow (GPM)
73	100	103	74.5	1.35	1.56
	110	109	77.0	1.25	1.44
	120	115	79.6	1.16	1.34
83	100	112	84.2	1.29	1.49
	110	116	88.1	1.26	1.46
	120	120	92.0	1.23	1.42
Note: All precipitation rates calculated for 180 degree operation. For precipitation rate of 360 degree sprinkler divide by 2.

ST-90 / STG-900 Dimensions Chart

	ST-90 *	STG-900 *
Overall Height	11-1/2"	14"
Pop-up Height	3"	3"
Exposed Diameter	5-1/2"	8"
Inlet Size	1-1/2" NPT	1-1/2" Acme
	*Not for use with the ST Enclosure	*For use with the ST173026B Enclosure