Hallo Prahlad,

if I would have to do with solenoid valve and SSR I would start with something like this:



In the left you see the 80C51 micro. When Port x,y goes low, outputs of 74HC04 inverters are going high. As consequence, opto inside SSR is turned-on and at the next zero crossing the SSR is fired. This will activate the solenoid valve.
If Port x,y goes high again after some time, outputs of 74HC04 inverters are going low. As consequence, SSR is turned-off and the solenoid valve is inactivated.

Keep in mind, that this circuit assumes a solenoid valve with negligible inductivity! Means, solenoid valve is expected to be mainly resistive.

In order to provide about 15mA driving current for the opto LED, four 74HC04 inverters are connected in parallel. Those 51R resistors are necessary to prevent 'hogging'.
Driver stage is working in negative logic, will say, SSR is fired, when Port x,y goes low.

As I stated in my last reply, a bit care must be taken to the output side of SSR, means some filtering is necessary to suppress high du/dt glitches and overvoltages. So, you will find standard snubber in the schematic, consisting of 100nF/630V capacitor and 100R resistor. At the mains line side there's a mains filter, providing a suppression of fast voltage glitches. Remember, that glitches of high du/dt can eroneously trigger the SSR. A VDR additionally helps to suppress overvoltages, which could otherwise destroy SSR. The two 1M resistors shall help to discharge the involved capacitors after removing mains voltage, and by this reduce the risk of electrical shock, when experimenting with unplugged circuitry.

In every opto coupler circuitry there's always a certain path for interference travelling from input to output or vice versa: The stray cpacitance between input and output, concretely spoken between opto LED and opto transistor. Because stray capacitance is in the pico Farad range, crosscoupling is 'improved' at high frequencies. Mains filter is very helpful in suppressing of interference coming from 'outer world', because the filter dampening is for high frequencies very good. So, it's not easy for interference running on mains line to jump over the opto link into the microcontroller section. But nevertheless, the SSR can produce interference itself, which can couple to input side. A good methode to handle such capacitive crosscoupling is to drive the opto LED by a low impedant source.
Of course, it would also have been possible to drive the opto LED by a PNP transistor. But if this transistor is turned-off, source impedance of driver is rather high impedant and interference isn't suppressed very much. A push pull driver is a better solution.

But what about the interference which once has reached the 74HC04 inverter outputs? The capacitive cross coupled noise is shunted to 0V of microcontroller circuit. Either directly, if outputs of 74HC04 inverters are in low state, or via decoupling capacitor next to 74HC04 chip, when inverter outputs are in high state. But in any case there will be something 'unwanted' at this local 0V point and it's wise to think about, what the possible consequences can be!
The injected noise will not rest there but travel back to the origin where it came from: Mains voltage, and everything that is connected to it, like transformers of power supply units (think of interwinding capacitance between primary and secondary winding!) and points connected to protection earth. So, think about where the noise current will travel along and arrange your board in such a way, that no such noise current is travelling over the microcontroller section and other sensible areas!
In any case use a PCB with solid ground plane. Only by this, voltage drops of these noise currents will be kept minimal.

Kai